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Chapter 6
Flash Memory
Preliminary User’s Manual U17566EE1V2UM00
The µPD70F3420 128 KB flash memory is made up of 32 blocks.
Figure 6-3
shows the address assignment of the flash memory blocks.
Figure 6-5
Address assignment of µPD70F3420 flash memory blocks
6.1.2
Flash memory erasure and rewrite
The following functions can be carried out by use of the flash memory self-
programming library.
(1)
Flash memory erasure
According to it’s block structure the flash memory can be erased in two
different modes.
• All-blocks batch erasure
Following areas can be erased all together:
– µPD70F3427, µPD70F3426, µPD70F3425: 0000 0000
H
to 000F FFFF
H
– µPD70F3424, µPD70F3423: 0000 0000
H
to 0007 FFFF
H
– µPD70F3422: 0000 0000
H
to 0005 FFFF
H
– µPD70F3421: 0000 0000
H
to 0003 FFFF
H
– µPD70F3420: 0000 0000
H
to 0001 FFFF
H
• Block erasure
Each 4 KB flash memory block can be erased separately.
(2)
Flash memory rewrite
Once a complete block has been erased it can be rewritten in units of 8 byte.
Each unit can be rewritten only once after erasure of the complete block.
0002 0000
H
0001 F000
H
0001 E000
H
0000 2000
H
0000 1000
H
0000 0000
H
Block 0 (4 KB)
Block 1 (4 KB)
Block 30 (4 KB)
Block 31 (4 KB)
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