CAT24C208

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6

Figure 6. Random Access Read (Segment 00h only)

WORD OFFSET

START

1010 0000

ACK

A7 − A0 ADDRESS

ACK

START

1010 0001

ACK

DATA

NOACK

STOP

Figure 7. Sequential Read (Segment 00h only)

WORD OFFSET

START 1010 0000 ACK A7 − A0 ADDRESS ACK START 1010 0001 ACK DATA0 ACK ......... DATAN NOACK STOP

Figures 8 and 9 show the byte and page write respectively. The configuration register must have the WE bit set to 1 prior

to any write on DDC Port. Only the segment 00h can be accessed of either lower or upper bank.

Figure 8. Byte Write (Segment 00h only)

WORD OFFSET

START

1010 0000

ACK

A7 − A0 ADDRESS

ACK

ACK

DATA

STOP

Figure 9. Page Write (Segment 00h only)

WORD OFFSET

START

1010 0000

ACK

A7 − A0 ADDRESS

ACK

DATA0

ACK

.........

DATA15

ACK

STOP

The segment pointer is at the address 60h and is

write−only. This means that a memory access at 61h will

give undefined results. The segment pointer is a volatile

register. The device configuration register at 62/63 (hex) is

a non−volatile register. The configuration register will be

shipped in the erased (set to FFh) state.

The segment pointer is used to expand the available DDC

address space while maintaining backward compatibility

with older DDC interfaces such as DDC2B. For each value

of the 8−bit segment pointer one segment (256 bytes) is

available at the A0/A1 pair. The standard DDC 8−bit address

is sufficient to address each of the 256 bytes within a

segment. Note that if the segment pointer is set to 00h then

the device will behave like a standard DDC2B EEPROM.

Read and write with segment pointer can expand the

addressable memory to 512 bytes in each bank with

wraparound to the next segment in the same bank only. The

two banks can be individually selected by the configuration

register and EDID Sel pin, as shown in Table 10. The

segment address.

Figures 10 to 13 show the random read, sequential read,

byte write and page write.

Figure 10. Random Access Read

START

1010 0000

ACK

A7 − A0 ADDRESS

ACK

START 1010 0001 ACK

DATA NOACK STOP

START

0110 0000

ACK

ACK

Figure 11. Sequential Read

START 1010 0000 ACK

A7 − A0 ADDRESS

ACK

START 1010 0001 ACK DATA0 ACK ......... DATAN NOACK STOP

START 0110 0000 ACK

ACK

Figure 12. Byte Write

START 1010 0000 ACK

A7 − A0 ADDRESS

ACK

DATA

ACK

STOP

START 0110 0000 ACK

ACK

Figure 13. Page Write

START 1010 0000 ACK

A7 − A0 ADDRESS

ACK

DATA0

ACK

.........

DATA15

ACK

STOP

START 0110 0000 ACK

ACK