CS4210 datasheet(31/102 Pages) NSC

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Operational Description (Continued)

3.9

SERIAL EEPROM

A serial EEPROM may be used to configure the CS4210. If

a serial EEPROM device is connected, the CS4210 detects

the pull-up resistor on the EEDATA pin (pin 5) and consid-

ers the EEPROM present. Immediately after RST# is deas-

serted, the serial EEPROM is scanned via EEDATA and

EECLK (pin 4). The CS4210 reads configuration informa-

tion from the first 34 bytes of the EEPROM.

If the presence of the serial EEPROM was not detected,

the CS4210 will not attempt to load configuration data via

the EEDATA/EECLK pins. It will instead allow software to

write to the guidHi and guidLo bit fields of the GUID regis-

ter once after each hardware reset (RST#).

3.9.1

Serial EEPROM Cyclic Redundancy Check

The serial EEPROM uses a Cyclical Redundancy Check

(CRC) to insure the data in the EEPROM is valid. If the

CRC check fails, the data from the EEPROM is not loaded

into the mapped registers listed in Table 3-11. The CRC1

and CRC2 values may be computed using the sample

code in Figure 3-1 "CRC1 and CRC2 Sample Code" on

page 32. This code accepts hexadecimal data from STDIN

and writes data plus CRC to STDOUT. As a check, this

code should produce the results as shown in Figure 3-1.

Table 3-11. Serial EEPROM Map

Offset

Description

00h

subsystem[7:0]

01h

subsystem[15:8]

02h

subsystem[23:16]

03h

subsystem[31:24]

04h

configROMheader[7:0]

05h

configROMheader[15:8]

06h

configROMheader[23:16]

07h

configROMheader[31:24]

08h

busOptions[7:0]

09h

busOptions[15:8]

0Ah

busOptions[23:16]

0Bh

busOptions[31:24]

0Ch

guidHi[7:0]

0Dh

guidHi[15:8]

0Eh

guidHi[23:16]

0Fh

guidHi[31:24]

10h

guidLo[7:0]

11h

guidLo[15:8]

12h

guidLo[23:16]

13h

guidLo[31:24]

14h

nscControl[7:0]

15h

nscControl[15:8]

16h

nscControl[23:16]

17h

nscControl[31:24]

18h

nscTxThrsh[7:0]

19h

nscTxThrsh[15:8]

1Ah

nscTxThrsh[23:16]

1Bh

nscTxThrsh[31:24]

1Ch

cmcControl[7:0]

1Dh

cmcControl[15:8]

1Eh

cmcControl[23:16]

1fh

cmcControl[31:24]

20h

CRC1

21h

CRC2

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