M32CSLASH8B datasheet(332/406 Pages) RENESAS

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M32C/8B Group

23. Flash Memory

Preliminary specification

Specifications in this manual are tentative and subject to change.

REJ09B0450-0050 Rev.0.50 Oct 31, 2008

Page 315 of 385

(7) Read Lock Bit Status Command

The read lock bit status command reads a lock bit status of a given block.

If the FMR31 bit in the FMR3 register is set to 1 (read by the FMR16 bit in the FMR1 register), the lock bit

status of the specified block is stored into the FMR16 bit by writing the command code xx71h in the first bus

cycle and xxD0h to the highest-order even address of the block in the second bus cycle. Read the FMR16 bit

after the FMR00 bit in the FMR0 register becomes 1 (ready).

If the FMR31 bit in the FMR3 register is set to 0 (read via the data bus), execute the read lock bit status

command by the program placed in the RAM. By writing xx71h in the first bus cycle and reading any even

address of the specified block in the second bus cycle, the lock bit status of the block can be read by the bit 6 of

the read data. When the bit 6 is 0, the block is locked; when the bit 6 is 1, the block is unlocked.

Figure 23.12 shows a flow chart of read lock bit status command.

Figure 23.12

Read Lock Bit Status Command

End

Read FMR16 bit

FMR00 = 1?

YES

Write the command code xx71h

Write xxD0h to the highest-order

even address of block

NOTES:

1. Write command code and data to even address.

2. Write command code and data by the program placed in the RAM.

3. The flash memory enters read array mode after this command is executed.

4. The flash memory enters read lock bit status mode after this command is executed. A lock bit status can be

read in succession by reading any even address of the specified block.

Write the command code xx71h(2)

Read any even address of block

Read the bit 6 of the read data

[When the FMR31 bit is 1] (Note 3)

[When the FMR31 bit is 0] (Note 4)

(Note 1)

End

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