cs4237b Cirrus Logic, Inc., cs4237b Datasheet - Page 22

• Manufacturer Part Number: cs4237b
• Description: Crystalclear Advanced Audio System With 3d Sound
• Manufacturer: Cirrus Logic, Inc.

MM7-MM0
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.
22
HW Config. Byte 6: COMbase Address Length
Mask, Default = 00000011
MM7
D7
MM6
D6
MM5
D5
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
MM4
D4
MM3
D3
MM2
D2
MM1
D1
MM0
D0
ACDB7D
SDD
VCEN
IHM
CKD
PKD
IHS
IHCD
HW Config. Byte 7: Misc. Configuration Bits,
Default = 10000000
IHCD
D7
IHS
D6
PKD
D5
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.
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.
the UP, DOWN, and MUTE pins be-
come active and provide a hardware
master volume control.
Interrupt High - Modem (LD5). When
set, MINT is active high. When clear,
MINT is active low.
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.
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.
Interrupt High - Synthesizer. When
set, SINT is active high. When clear,
SINT is active low.
Interrupt High - CDROM. When set,
CDINT is active high. When clear,
CDINT is active low.
Volume Control Enable. When set,
PnP Key disable. When set, blocks
CKD
D4
IHM
D3
VCEN
D2
SDD
D1
CS4237B
DS213PP4
ACDB7D
D0