LM4560 datasheet(45/54 Pages) NSC

45 / 54 page

4.0 Functional Description (Continued)

E2h command is used to compute the subroutine’s starting address for digital sound playback or recording according to the dedi-

cated algorithm. The resultant byte should be sent back to system memory via legacy DMA operation method (two bytes trans-

ferred in all). After E2h is received, ESP will be set busy if E2Status (source from wave engine) is set active.

4.2.1.14.4 Command E4h

Function: Send Test Byte for Command E8h

4.2.1.14.5 Command E8h

Function: Get Test Byte Sent by Command E4h

4.2.1.15 SB ESP Testing Command FXh

4.2.1.15.1 Command F2h

Function: Generate an interrupt for test

SB ESP will generate an interrupt immediately after this command.

4.2.1.15.2 Command F8h

Function: SB ESP data read test

4.2.1.16 Digitized Sound Data Format and Order

4.2.1.16.1 PCM Sound Data Format

Length

Format

Max. Value

Min. Value

Mid. Value

8 Bit

Unsigned FFh

80h

8 Bit

Signed

7Fh

80h

16 Bit

Unsigned FFFFh

8000h

16 Bit

Signed

7FFFh

8000h

4.2.1.16.2 PCM Sound Data Order

4.2.1.16.2.1 8-Bit Mono

N+1

N+2

N+3

N+4

PCM 0

PCM 1

PCM 2

PCM 3

PCM 4

4.2.1.16.2.2 8-Bit Stereo for 1xh and 9xh Type Command

2N+1

2(N+1)+0

2(N+1)+1

2(N+2)+0

PCM 0.R

PCM 0.L

PCM 1.R

PCM 1.L

PCM 2.R

4.2.1.16.2.3 8-BIT STEREO FOR CXH TYPE COMMAND

2N+1

2(N+1)+0

2(N+1)+1

2(N+2)+0

PCM 0.L

PCM 0.R

PCM 1.L

PCM 1.R

PCM 2.L

4.2.1.16.2.4 16-Bit Mono

2N+1

2(N+1)+0

2(N+1)+1

2(N+2)+0

LOW

HIGH

LOW

HIGH

LOW

PCM 0

PCM 1

PCM 2

4.2.1.16.2.5 16-Bit Stereo

4N+1

4N+2

4N+3

4(N+1)+0

LOW

HIGH

LOW

HIGH

LOW

PCM 0.L

PCM 0.R

PCM 1.L

4.2.1.17 Legacy Sound Blaster Mixer Register

The legacy SB mixer register are accessed through indirect addressing method, where the SBR4 stores the index of addressed

register and SBR5 stores the register content to be read/write. In the following description, MXxx represents a mixer register

whose index is xx.

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