CS4237B Datasheet, PDF (113/114 Pages) Cirrus Logic – CrystalClear Advanced Audio System with 3D Sound

CS4237B
The added features over the CS4236 are as follows:
10. SRS 3D Sound Technology is added and is controlled through C2 and C3 registers.
11. A Wavetable Serial Port interface is added for connection to the CS9236 Single-Chip Wavetable
Music Synthesizer. The pins are multiplexed with the XD7-XD5 pins and are controlled by the
WTEN bit in C8 or the Global Configuration byte in the Hardware Configuration data.
12. The DSP serial port can be multiplexed to the XD4-XD1 pins to allow the DSP serial port and the
second joystick to be used simultaneously. The multiplexing is controlled by the SPS bit in C8 or
the Global Configuration byte in the Hardware Configuration data.
13. Hardware volume control supports 4 formats.
14. New bits are added to the Global Configuration byte of the Hardware Configuration data:
VCF1 and VCF0 Hardware Volume Control Format bits
SLAD which disables Sound Blaster Synthesis volume changes from affecting LINE volume.
WTEN to enable the Wavetable Serial Port
SPS to switch the DSP serial port pins from the second joystick to the XD4-XD1 pins
15. The Consumer digital audio transmission format supported on the DSP serial port through the C4-
C6 registers is new.
16. Serial Port Format 3 (I16) is a new DSP serial port format.
17. A symmetrical mixer (the input mixer is new) is included and is supported by a new mode,
MODE 3. This mode is enabled by setting the CMS1,0 bits in WSS I12 to 11. Note that the
CS4236 MODE2 bit has been renamed CMS1 (Codec Mode Select 1). CMS1 is backwards compat-
ible with the CS4236 MODE2 bit.
18. The MIC can be mixed directly to the output mixer with full volume control.
19. Hardware Configuration byte 9 was reserved in the CS4236 (at 0x43) and is now used as a Code
Base Byte that determines the firmware code compatibility in the E²PROM. When firmware code
for this part is loaded in the E²PROM this byte must be changed to 0x0B. This provides backwards
compatibility by ignoring CS4236-based firmware code, which has this byte set to 0x43, while still
reading the Hardware Configuration and PnP data from CS4236-programmed E²PROM.
20. 3.3 Volt ISA bus support is added. This includes all ISA pins except DRQA (which still runs at
5 Volts). When the VD1 pin is powered from a 3.3 Volt supply, the ISA bus connected to it must
also run at 3.3 Volts.
DS213PP4
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