Rainbow Electronics T48C862-R8 - Manual (Page 93)

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T48C862-R8
4590B–4BMCU–02/03
Write Control Bytes
A -> acknowledge; HB: high byte; LB: low byte; R: row address
Read Operations The EEPROM allows byte-, word- and current address read operations. The read oper-
ations are initiated in the same way as write operations. Every read access is initiated by
sending the START condition followed by the control byte which contains the address
and the read mode. When the device has received a read command, it returns an
acknowledge, loads the addressed word into the read/write buffer and sends the
selected data byte to the master. The master has to acknowledge the received byte if it
wants to proceed the read operation. If two bytes are read out from the buffer the device
increments respectively decrements the word address automatically and loads the
buffer with the next word. The read mode bits determines if the low or high byte is read
first from the buffer and if the word address is incremented or decremented for the next
read access. If the memory address limit is reached, the data word address will roll over
and the sequential read will continue. The master can terminate the read operation after
every byte by not responding with an acknowledge (N) and by issuing a stop condition.
Read One Data Byte
Read Two Data Bytes
Read n Data Bytes
Read Control Bytes
MSB LSB
Write low byte first A4 A3 A2 A1 A0 C1 C0 R/NW
Row address 0 1 0
Byte order LB(R) HB(R)
MSB LSB
Write high byte first A4 A3 A2 A1 A0 C1 C0 R/NW
Row address 1 0 0
Byte order HB(R) LB(R)
Start Control byte A Data byte 1 N Stop
Start Control byte A Data byte 1 A Data byte 2 N Stop
Start Control byte A Data byte 1 A Data byte 2 A - - - Data byte n N Stop
MSB LSB
Read low byte first,
address increment
A4 A3 A2 A1 A0 C1 C0 R/NW
Row address 0 1 1
Byte order LB(R) HB(R) LB(R+1) HB(R+1) - - - LB(R+n) HB(R+n)
MSB LSB