CS4237B Datasheet, PDF (22/114 Pages) Cirrus Logic – CrystalClear Advanced Audio System with 3D Sound

CS4237B
HW Config. Byte 6: COMbase Address Length
Mask, Default = 00000011
D7 D6 D5 D4 D3 D2 D1 D0
MM7 MM6 MM5 MM4 MM3 MM2 MM1 MM0
MM7-MM0
Address bit masks for Logical Device
5, typically a modem address,
COMbase. See the Modem Interface
Section for more details on
COMbase.
00000000 - MCS low for 1 byte
00000001 - MCS low for 2 bytes
00000011 - MCS low for 4 bytes
00000111 - MCS low for 8 bytes
00001111 - MCS low for 16 bytes
00011111 - MCS low for 32 bytes
00111111 - MCS low for 64 bytes
01111111 - MCS low for 128 bytes
11111111 - MCS low for 256 bytes
xxxxxxxx - all others, RESERVED
NOTE: The part only buffers the lower three address
bits onto the peripheral port. When setting the ad-
dress decode greater than 8 bytes, the upper
address bits should be buffered externally.
HW Config. Byte 7: Misc. Configuration Bits,
Default = 10000000
D7 D6 D5 D4 D3
IHCD IHS PKD CKD IHM
D2
VCEN
D1 D0
SDD ACDB7D
ACDB7D
Alternate CDROM, data Bit 7 Disable.
When set, SD7 is held in a high
impedance state when reading from
ACDbase+1 (only this one address).
This bit provides support for IDE al-
ternate base address sharing with
the floppy disk controller.
SDD
SD Disable. When set, SD<7:0> are
high impedance on reads from any
peripheral port address: External syn-
thesis, CDROM or Modem devices.
Allows external buffers to bypass the
part while still allowing PnP address
support. This bit is also internally
forced on whenever WTEN or SPS
in HW Config. byte 8, or C8, is set.
VCEN
Volume Control Enable. When set,
the UP, DOWN, and MUTE pins be-
come active and provide a hardware
master volume control.
IHM
Interrupt High - Modem (LD5). When
set, MINT is active high. When clear,
MINT is active low.
CKD
Crystal Key disable. When set, blocks
the part from receiving the Crystal
key. Note that if both CKD and PKD
are set, software will be unable to re-
configure the part.
PKD
PnP Key disable. When set, blocks
the part from receiving the Plug-and-
Play key. Note that if both CKD and
PKD are set, software will be unable
to reconfigure the part.
IHS
Interrupt High - Synthesizer. When
set, SINT is active high. When clear,
SINT is active low.
IHCD
Interrupt High - CDROM. When set,
CDINT is active high. When clear,
CDINT is active low.
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