cs4239 Cirrus Logic, Inc., cs4239 Datasheet - Page 26

• Manufacturer Part Number: cs4239
• Description: Crystalclear? Ortable Isa Audio System Logic
• Manufacturer: Cirrus Logic, Inc.

The new PnP data is loaded and the part is ready
for the next PnP cycle.
External E
The Plug and Play specification defines 32 bits
of the 72-bit Serial Identifier as being a user de-
fined serial number. The E
change the user section of the identifier, store
default resource data for PnP, Hardware Con-
figuration data specific to the CS4239, and
firmware patches to upgrade the core processor
functionality.
The E
2-wire interface consisting of a bi-directional
data line and a clock line driven from the part.
After power-on the part looks for the existence
of an E
fined data. The existence is determined by the
first two bytes read (0x55 followed by 0xBB). If
the first two bytes are correct, the part reads the
next two bytes to determine the length of data in
the E
number of bytes left to be read (not including
26
4. Download Firmware data. To download
5. If any of the Hardware Configuration Data
firmware data, contact Cirrus Logic for the
ISA Audio BIOS kit.
(first 19 bytes) has changed, 5Ah must be
written to CTRLbase+5 to force the part to
internally update this information.
c. Send the Hardware Configuration and re-
d. End download by writing 00h to
sour ce data in successive bytes to
CTRLbase+5. This includes the Hardware
Configuration and the PnP resource data.
The PnP resource format is described in
the PnP Data section. The resource header
should not contain the first four bytes
which are only used for E
CTRLbase+6.
2
2
PROM interface uses an industry standard
PROM. The length bytes indicate the
2
PROM device and loads the user de-
2
PROM
2
PROM is used to
2
PROM loads.
the two validation bytes or two length bytes). As
shown in Figure 3, the E
start bit followed by a dummy write, to initialize
the address to zero. Then another start bit and
device address, followed by all the data. Since
the part uses the sequential read properties of the
E
(ganged E
Some E
interface are:
where the xx is replaced by 02, 04, 08, or 16
based on the size of the E
size of 08 (1k bytes) is preferred since it allows
the maximum flexibility for upgrading firmware
patches. Other E
ure 3 and the timing parameters listed in the
front of the data sheet may also be used.
The maximum Hardware Configuration and PnP
resource RAM data supported is 384 bytes, and
a four byte header; therefore, the maximum
amount of data storage, without firmware
patches, in E
maximum size E
allow the inclusion of firmware patches after the
PnP resource data.
If an external E
the serial interface and is connected to the SDA
and SCL pins. The two-wire interface is control-
led by three bits in the Control logical device,
Hardware Control Register (CTRLbase+1). The
serial data can be written to or read from the
E
register. The three register bits, D0, D1, D2 are
labeled CLK, DOUT, and DIN/EEN respectively.
The DIN/EEN bit, when written to a one, en-
ables the E
DIN/EEN bit is written to a zero, the serial inter-
2
2
PROM, only one E
PROM by sequentially writing or reading that
Atmel
MicroChip
National
Ramtron
SGS Thompson
Xicor
CrystalClear Portable ISA Audio System
2
PROMs that are compatible with this
2
PROMs are not supported).
2
PROM serial interface. When the
2
PROM would be 388 bytes. The
2
2
PROM exists, it is accessed by
2
PROM needed is 770 bytes, to
PROMs compatible with Fig-
TM
AT24Cxx series
ST24Cxx series
24LCxxB series
NM24CxxL series
FM24Cxx series
X24Cxx series
2
2
PROM is read using a
PROM, is supported
2
PROM desired. The
CS4239
DS253PP2