MB85AS12MT

12

DS501-00071-1v1-E



WRITING OPERATION OF NONVOLATILE MEMORY

Each input data is not written to the nonvolatile memory by unit of byte right after its data input. Multiple

bytes up to maximum 256 bytes are temporarily saved to the data register. After the command input is

finished and rising edge of CS, start writing operation from this data register to the nonvolatile memory.

1. Address counter control

In case of memory access by WRITE and READ commands, after the end of op-code and address input, it

is possible to keep on accessing (= reading or writing) with automatic address increment which is enabled

by continuously sending clocks to SCK in unit of 8 cycles while CS is low level. However, for the WRITE

command, continuous writing is restricted by the limit of buffer size in the data register.

When it reaches the most significant address, it rolls over to the starting address, and this automatic address

increment will be continued by the address counter control.

Over write protection to the nonvolatile memory is enabled by BP0 and BP1 bits in status register. When the

memory address exceed it from write protected block to unprotected block by address counter control, write

to the unprotected block only. Similarly, when memory address exceed it from unprotected block to protected

block, does not write to the protected block.

0

7

bit number

654321

Start address

Start address+1

Start address+2

Most significant address-5

Most significant address-4

Most significant address-3

Most significant address-2

Most significant address-1

Most significant address

MSB

LSB