Sound Blaster 16: Difference between revisions
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The Sound Blaster series is a family of sound cards made by Creative. For many years they were the standard audio cards on IBM PC's. |
The Sound Blaster series is a family of sound cards made by Creative. For many years they were the standard audio cards on IBM PC's. |
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! Port |
! Port |
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! Description |
! Description |
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|- |
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| 0x224 || DSP Mixer port |
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|- |
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| 0x225 || DSP Mixer data port |
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|- |
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| 0x226 || DSP Reset |
| 0x226 || DSP Reset |
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| 0x22A || DSP Read |
| 0x22A || DSP Read |
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|- |
|- |
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| 0x22C || DSP Write |
| 0x22C || DSP Write (Read this port for Write Status) |
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|- |
|- |
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| 0x22E || DSP Read Status (Read this port to acknowledge 8-bit interrupt) |
| 0x22E || DSP Read Status (Read this port to acknowledge 8-bit interrupt) |
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{| {{wikitable}} |
{| {{wikitable}} |
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! Command |
! Command |
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! Description |
! Description |
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! Output/input for command |
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|- |
|- |
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| 0x41 || Set Output Sample Rate |
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|- |
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| 0xB6 || Auto transfer mode |
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| 0x41 || Set Output Sample Rate || high bit/low bit |
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|- |
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| 0xD5 || Stop playing |
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|- |
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| 0xE1 || Get DSP version |
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|- |
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| 0xD0 || Stop playing 8 bit channel || |
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|- |
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| 0xD5 || Stop playing 16 bit channel || |
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|- |
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| 0xE1 || Get DSP version || major version/minor version |
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|- |
|- |
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|} |
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When the samples have been played, an interrupt will be fired, and the OS/Driver will have the chance to refill the buffer, or to issue a Stop command. |
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{| {{wikitable}} |
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! Command for Mixer port |
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! Description |
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! Mixer data port |
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|- |
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| 0x22 || Master volume || 0xLR L=left volume R=right volume min=0x0 max=0xF (default value is 0xCC or 0x11) |
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|- |
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| 0x80 || Set IRQ || See below |
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|- |
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|} |
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Because you only have a single DMA buffer to transfer data, it is recommended that you issue the Play PCM command with a sample count of half of the data buffer. This will fire an interrupt when the buffer is half played, allowing you to refill the segment that was just played, while the DSP continues playing the other half, and so on. |
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There are two modes for transfering data. First is single mode - data from buffer are played, interrupt is fired and playing is stopped. It make lower quality of sound. Second is auto mode - data from buffer are playing forever and interrupt is fired after play buffer. You should use interrupt for re-filling buffer. |
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===Reading and writing=== |
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==Operations== |
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Until you write to the DSP write port, check the DSP write port for 0x00. Until reading the DSP read port, check the DSP status port for 0x80. |
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== |
==Detecting DSP== |
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Detecting DSP is really easy. You must send to DSP reset port 1, wait 3 microseconds, send to DSP reset 0 and read DSP read port. If in it is 0xAA, DSP exist. Some SB-compatible cards returned 0xAA on first check but on second check they reported their specific version. |
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# Send 1 to DSP reset port |
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# Wait 3 microseconds |
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# Send 0 to DSP reset port |
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# Now should be in DSP read port 0xAA. |
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Some SB-compatible cards returned 0xAA on first check but on second check they reported their specific version. |
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== |
==Playing sound== |
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# Detect DSP |
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# Send 0x80 to Mixer port |
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# Load sound data to memory |
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# Send value of your IRQ to Mixer data port |
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# Program ISA DMA |
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0x01=IRQ 2 0x02=IRQ 5 0x04=IRQ 7 0x08=IRQ 10 Usually is used IRQ 5. You can read this port too for get actual IRQ. |
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# Set output sample rate(command/High byte/Low byte) |
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# Write DMA transfer type to DSP(command) |
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# Write data lenght to DSP(Low byte/High byte) |
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===Programming DMA=== |
===Programming DMA=== |
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You can get more info about programming DMA on page [http://homepages.cae.wisc.edu/~brodskye/sb16doc/sb16doc.html] . |
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Programming 8 bit transfers throught channel 1 (channel number is 1): |
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# Disable channel by writing to port 0x0A value 0x05 (channel number + 0x04) |
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# Write value to flip-flop port 0x0C (any value e.g. 1) |
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# Send transfer mode to 0x0B (0x48 for single mode/0x58 for auto mode + channel number) |
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# Send page number to 0x83(page port of channel 1) For example if you have sound data at 0x100450, page is 0x10. |
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# Send low bits of position to port 0x02(addr. port of channel 1) For example(see above) is 0x50. |
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# Send high bits of position to port 0x02(addr. port of channel 1) For example(see above) is 0x04. |
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# Send low bits of lenght of data to port 0x03(count port of channel 1) For example if is lenght 0x0FFF, send 0xFF |
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# Send high bits of lenght of data to port 0x03(count port of channel 1) For example if is lenght 0x0FFF, send 0x0F |
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# Enable channel by writing channel number to port 0x0A |
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Programming 16 bit transfers throught channel 5 (channel number is 1 too): |
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# Disable channel by writing to port 0xD4 value 0x05 (channel number + 0x04) |
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# Write value to flip-flop port 0xD8 (any value e.g. 1) |
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# Send transfer mode to 0xD6 (0x48 for single mode/0x58 for auto mode + channel number) |
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# Send page number to 0x8B(page port of channel 5) For example if you have sound data at 0x100450, page is 0x10. |
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# Send low bits of position to port 0xC4(addr. port of channel 5) For example(see above) is 0x50. |
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# Send high bits of position to port 0xC4(pos. port of channel 5) For example(see above) is 0x04. |
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# Send low bits of lenght of data to port 0xC6(count port of channel 5) For example if is lenght 0x0FFF, send 0xFF |
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# Send high bits of lenght of data to port 0xC6(count port of channel 5) For example if is lenght 0x0FFF, send 0x0F |
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# Enable channel by writing channel number to port 0xD4 |
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===Writing transfer mode to DSP=== |
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Usually values are 0xB0 for 16 bit playing sound or 0xC0 for 8 bit playing sound. |
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{| {{wikitable}} |
{| {{wikitable}} |
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! |
! Port |
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! Description |
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! Bit 3 |
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! Bit 2 |
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! Bit 1 |
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! Bit 0 |
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|- |
|- |
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| 0xC4 || Address |
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| 0xB=16 bit transfer 0xC=8 bit transfer || 0=playing sound 1=recording sound || 0 || 0=FIFO off 1=FIFO on || 0 |
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|- |
|- |
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| 0xC6 || Count |
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|} |
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===Writing type of sound data to DSP=== |
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You must write type of sound data after write transfer mode. |
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{| {{wikitable}} |
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! Bit 7 |
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! Bit 6 |
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! Bit 5 |
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! Bit 4 |
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! Bit 3 |
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! Bit 2 |
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! Bit 1 |
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! Bit 0 |
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|- |
|- |
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| 0x8B || Page |
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| 0 || 0 || 0=mono 1=stereo || 0=unsigned 1=signed || 0 || 0 || 0 || 0 |
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|- |
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| 0xD4 || Single mask |
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|- |
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| 0xD6 || Transfer mode |
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|- |
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| 0xD8 || Clear pointer |
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|- |
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|} |
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==Playing sound== |
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# Reset DSP |
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# Load sound data to memory |
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# Set master volume |
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# Turn speaker on |
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# Program ISA DMA to transfer |
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# Set time constant |
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# Set output sample rate |
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# Write transfer mode to DSP |
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# Write type of sound data |
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# Write data lenght to DSP(Low byte/High byte) (You must calculate LENGHT-1 e.g. if is your real lenght 0x0FFF, you must send 0xFE and 0x0F) |
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==Code== |
==Code== |
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<source lang=" |
<source lang="C"> |
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//Digital Sound Processor ports |
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%macro OUTB 2 |
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#define DSP_RESET 0x226 |
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mov dx, %1 |
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#define DSP_READ 0x22A |
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mov al, %2 |
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#define DSP_WRITE 0x22C |
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out dx, al |
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#define DSP_BUFFER 0x22A |
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%endmacro |
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#define DSP_STATUS 0x22E |
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#define DSP_INTERRUPT 0x22F |
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%macro INB 1 |
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mov dx, %1 |
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in al, dx |
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%endmacro |
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//Digital Sound Processor commands |
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#define DSP_CMD_OUTPUT_RATE 0x41 |
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#define DSP_CMD_TRANSFER_MODE 0xB6 |
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#define DSP_CMD_STOP 0xD5 |
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#define DSP_CMD_VERSION 0xE1 |
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//DMA ports |
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;SOUND BLASTER 16 driver in real mode |
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#define DMA_ADDRES 0xC4 |
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#define DMA_COUNT 0xC6 |
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#define DMA_PAGE 0x8B |
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#define DMA_SINGLE_MASK 0xD4 |
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#define DMA_TRANSFER_MODE 0xD6 |
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#define DMA_CLEAR_POINTER 0xD8 |
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void reset_DSP(void) { |
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;reset sound blaster |
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outb(DSP_RESET, 1); |
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OUTB 0x226, 1 ;reset port |
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sleep(3); //wait 3 microseconds |
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mov ah, 86h |
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outb(DSP_RESET, 0); |
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mov cx, 0x0000 |
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if(read_DSP()==0xAA) { |
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int 15h ;wait |
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sound_blaster=TRUE; |
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OUTB 0x226, 0 ;reset port |
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} |
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} |
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void sb16_init(void) { |
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;turn speaker on |
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reset_DSP(); |
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OUTB 0x22C, 0xD1 |
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//if DSP doesnt exist |
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;DMA channel 1 |
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if(sound_blaster==FALSE) { |
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OUTB 0x0A, 5 ;disable channel 1 (number of channel + 0x04) |
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return; |
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OUTB 0x0C, 1 ;flip flop |
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} |
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OUTB 0x0B, 0x49 ;transfer mode |
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OUTB 0x83, 0x01 ;PAGE TRANSFER (EXAMPLE POSITION IN MEMORY 0x[01]0F04) - SET THIS VALUE FOR YOU |
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OUTB 0x02, 0x04 ;POSITION LOW BIT (EXAMPLE POSITION IN MEMORY 0x010F[04]) - SET THIS VALUE FOR YOU |
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OUTB 0x02, 0x0F ;POSITON HIGH BIT (EXAMPLE POSITION IN MEMORY 0x01[0F]04) - SET THIS VALUE FOR YOU |
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OUTB 0x03, 0xFF ;COUNT LOW BIT (EXAMPLE 0x0FFF) - SET THIS VALUE FOR YOU |
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OUTB 0x03, 0x0F ;COUNT HIGH BIT (EXAMPLE 0x0FFF) - SET THIS VALUE FOR YOU |
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OUTB 0x0A, 1 ;enable channel 1 |
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//get DSP version |
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;program sound blaster 16 |
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write_DSP(DSP_CMD_VERSION); |
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OUTB 0x22C, 0x40 ;set time constant |
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sb16_version_major=read_DSP(); |
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OUTB 0x22C, 165 ;10989 Hz |
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sb16_version_minor=read_DSP(); |
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OUTB 0x22C, 0xC0 ;8 bit sound |
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OUTB 0x22C, 0x00 ;mono and unsigned sound data |
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OUTB 0x22C, 0xFE ;COUNT LOW BIT - COUNT LENGHT-1 (EXAMPLE 0x0FFF SO 0x0FFE) - SET THIS VALUE FOR YOU |
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OUTB 0x22C, 0x0F ;COUNT HIGH BIT - COUNT LENGHT-1 (EXAMPLE 0x0FFF SO 0x0FFE) - SET THIS VALUE FOR YOU |
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} |
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;now transfer start - dont forget to handle irq |
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</source> |
</source> |
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Revision as of 21:36, 21 May 2020
The Sound Blaster series is a family of sound cards made by Creative. For many years they were the standard audio cards on IBM PC's.
Introduction
The Sound Blaster 16 is the successor to the Sound Blaster Pro audio card found in many older computers. It was first brought out in 1992. The main improvement over the Pro is its 16-bit digital audio sampling (hence the name). Most SB16 cards are PCI compatible, as Creative made this improvement shortly after releasing the card, upgrading from ISA.
Digital Signal Processor
The DSP built into the Sound Blaster 16 supports playing and recording audio in 8-bit and 16-bit PCM encoded samples, along with playing several other formats (ADPCM, etc.). The base I/O register address can be found using the PCI bus for PCI models, or by detecting the presence of an older ISA Sound Blaster by issuing a Get Version command to one of several common I/O port addresses (0x220, 0x240, etc.) and waiting for a response.
Port | Description |
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0x226 | DSP Reset |
0x22A | DSP Read |
0x22C | DSP Write (Read this port for Write Status) |
0x22E | DSP Read Status (Read this port to acknowledge 8-bit interrupt) |
0x22F | DSP 16-bit Interrupt Acknowledge (Read this port to acknowledge 16-bit interrupt) (DSP Version 4.0+ Only) |
Command | Description |
---|---|
0x41 | Set Output Sample Rate |
0xB6 | Auto transfer mode |
0xD5 | Stop playing |
0xE1 | Get DSP version |
When the samples have been played, an interrupt will be fired, and the OS/Driver will have the chance to refill the buffer, or to issue a Stop command.
Because you only have a single DMA buffer to transfer data, it is recommended that you issue the Play PCM command with a sample count of half of the data buffer. This will fire an interrupt when the buffer is half played, allowing you to refill the segment that was just played, while the DSP continues playing the other half, and so on.
Reading and writing
Until you write to the DSP write port, check the DSP write port for 0x00. Until reading the DSP read port, check the DSP status port for 0x80.
Detecting DSP
Detecting DSP is really easy. You must send to DSP reset port 1, wait 3 microseconds, send to DSP reset 0 and read DSP read port. If in it is 0xAA, DSP exist. Some SB-compatible cards returned 0xAA on first check but on second check they reported their specific version.
Playing sound
- Detect DSP
- Load sound data to memory
- Program ISA DMA
- Set output sample rate(command/High byte/Low byte)
- Write DMA transfer type to DSP(command)
- Write data lenght to DSP(Low byte/High byte)
Programming DMA
Port | Description |
---|---|
0xC4 | Address |
0xC6 | Count |
0x8B | Page |
0xD4 | Single mask |
0xD6 | Transfer mode |
0xD8 | Clear pointer |
Code
//Digital Sound Processor ports
#define DSP_RESET 0x226
#define DSP_READ 0x22A
#define DSP_WRITE 0x22C
#define DSP_BUFFER 0x22A
#define DSP_STATUS 0x22E
#define DSP_INTERRUPT 0x22F
//Digital Sound Processor commands
#define DSP_CMD_OUTPUT_RATE 0x41
#define DSP_CMD_TRANSFER_MODE 0xB6
#define DSP_CMD_STOP 0xD5
#define DSP_CMD_VERSION 0xE1
//DMA ports
#define DMA_ADDRES 0xC4
#define DMA_COUNT 0xC6
#define DMA_PAGE 0x8B
#define DMA_SINGLE_MASK 0xD4
#define DMA_TRANSFER_MODE 0xD6
#define DMA_CLEAR_POINTER 0xD8
void reset_DSP(void) {
outb(DSP_RESET, 1);
sleep(3); //wait 3 microseconds
outb(DSP_RESET, 0);
if(read_DSP()==0xAA) {
sound_blaster=TRUE;
}
}
void sb16_init(void) {
reset_DSP();
//if DSP doesnt exist
if(sound_blaster==FALSE) {
return;
}
//get DSP version
write_DSP(DSP_CMD_VERSION);
sb16_version_major=read_DSP();
sb16_version_minor=read_DSP();
}