CS8900A-CQZ View Datasheet(PDF) - Cirrus Logic

Part Name

Description

Manufacturer

CS8900A-CQZ

Crystal LAN™ Ethernet Controller

Cirrus Logic 

CS8900A

Crystal LAN™ Ethernet Controller

initialization is complete (configuration loaded

from EEPROM or reset to default configura-

tion) the INITD bit is set (Register 16, SelfST,

bit 7).

3.5 Programming the EEPROM

After initialization, the host can access the EE-

PROM through the CS8900A by writing one of

seven commands to the EEPROM Command

register (PacketPage base + 0040h). Figure 5

shows the format of the EEPROM Command

register.

3.5.1 EEPROM Commands

The seven commands used to access the EE-

PROM are: Read, Write, Erase, Erase/Write

Enable, Erase/Write Disable, Erase-All, and

Write-All. They are described in Table 8.

Command

Read Register

Write Register

Erase Register

Erase/Write Enable

Erase/Write Disable

Erase-All Registers

Write-All Register

Opcode

(bits 9,8)

1,0

0,1

1.1

0,0

0,0

0,0

0,0

0,0

0,0

0,0

EEPROM Address Data

(bits 7 to 0)

EEPROM Type

word address

yes

all

word address

yes

all

word address

no

all

XX11-XXXX

no

‘CS46, ‘C46

11XX-XXXX

no

‘CS56, ‘C56, ‘CS66, ‘C66

XX00-XXXX

no

‘CS46, ‘C46

00XX-XXXX

no

‘CS56, ‘C56, ‘CS66, ‘C66

XX10-XXXX

no

‘CS46, ‘C46

10XX-XXXX

no

‘CS56, ‘C56, ‘CS66, ‘C66

XX01-XXXX

yes

‘CS46, ‘C46

01XX-XXXX

yes ‘CS56, ‘C56, ‘CS66, ‘C66

Table 8. EEPROM Commands

Execution

Time

25 µs

10 ms

10 ms

9 µs

9 µs

9 µs

9 µs

10 ms

9 µs

10 ms

10 ms

3.5.2 EEPROM Command Execution

Opcode bits, followed by the six bits of address

During the execution of a command, the two (for a ’C46 or ’CS46) or eight bits of address

AD 7 - AD0 used w ith 'C 56,

'C S56, 'C 66 and 'C S66

F EDCB A

9876543210

X X X X X ELSEL OP1 OP0 AD7 AD6 AD5 AD4 AD3 AD2 AD1 AD0

Bit

[F:B]

[A]

[9:8]

[7:0]

DS271F4

AD5 - AD0 used w ith

'C46 and 'CS46

Name

ELSEL

OP1, OP0

AD7 to AD0

Description

Reserved

External Logic Select: When clear, the EECS pin is used to select the EEPROM.

When set, the ELCS pin is used to select the external LA decode circuit.

Opcode: Indicates what command is being executed (see next section).

EEPROM Address: Address of EEPROM word being accessed.

Figure 5. EEPROM Command Register Format

CIRRUS LOGIC PRODUCT DATASHEET

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