PEDL9044-03
1
Semiconductor
ML9044-xxA/xxB
I/F with CPU
Parallel interface mode
The ML9044 can transfer either 8 bits once or 4 bits twice on the data bus for interfacing with any 8-bit or 4-bit
microcontroller (CPU).
1) 8-bit interface data length
The ML9044 uses all of the 8 data bus lines DB0 to DB7 at a time to transfer data to and from the CPU.
2) 4-bit interface data length
The ML9044 uses only the higher-order 4 data bus lines DB4 to DB7 twice to transfer 8-bit data to and from the
CPU.
The ML9044 first transfers the higher-order 4 bits of 8-bit data (DB4 to DB7 in the case of 8-bit interface data
length) and then the lower-order 4 bits of the data (DB0 to DB3 in the case of 8-bit interface data length).
The lower-order 4 bits of data should always be transferred even when only the transfer of the higher-order 4
bits of data is required. (Example: Reading the Busy Flag)
Two transfers of 4 bits of data complete the transfer of a set of 8-bit data. Therefore, when only one access is
made, the following data transfer cannot be completed properly.
30/60
OKI [ OKI ELECTRONIC COMPONETS ]
