Data Reading Procedure; Data Writing Procedure - Casio 110CR Service Manual

[Data reading procedure]

When the CPU read the dara of EEPROM, CPU send the CS signal and SK signal to EEPROM.
Then, CPU send the address to EEPROM, and then EEPROM send the data to CPU.
CS
SK
DI
DO

[Data writing procedure]

When the CPU save the data to EEPROM, CPU sends the CS and SK signal to EEPROM.
And CPU send the address and data to EEPROM from pin No.15.
When the EEPROM writes the data , EEPROM outputs the busy signal from DO terminal to CPU.
After finish writing, EEPROM outputs the ready signal from DO terminal to CPU.
CS
SK
DI
DO
High Impedance
Output data here
Address
- 7 -
Address
Data
Status
Data
BUSY(L)
READY(H)