120
Chapter 3
CPU System Functions
Preliminary User’s Manual U17566EE1V2UM00
(2)
Internal VDB RAM area
After reset
The internal VDB RAM consists of several separated RAM blocks. If a reset
occurs while writing to one RAM block, only the contents of that RAM block
may be corrupted. The contents of the other RAM blocks remain unaffected.
Table 3-12
summarizes the VDB (V850 Data Bus) RAM blocks compilation and
their address assignment.
Note that the internal firmware, which is processed after reset, uses some
RAM (refer to
“General reset performance“ on page 861
).
Table 3-12
Internal VDB RAM areas
Device
RAM size
Block
Number
Size
Address
µPD70(F)3420
6 KB
0
4 KB
03FF 0000
H
– 03FF 0FFF
H
1
2 KB
03FF 1000
H
– 03FF 17FF
H
µPD703421
12 KB
0
4 KB
03FF 0000
H
– 03FF 0FFF
H
1
4 KB
03FF 1000
H
– 03FF 1FFF
H
2
4 KB
03FF 2000
H
– 03FF 2FFF
H
µPD70F3421
12 KB
0
4 KB
03FF 0000
H
– 03FF 0FFF
H
1
8 KB
03FF 1000
H
– 03FF 2FFF
H
µPD70(F)3422
16 KB
0
8 KB
03FF 0000
H
– 03FF 1FFF
H
1
8 KB
03FF 2000
H
– 03FF 3FFF
H
µPD70F3423
20 KB
0
8 KB
03FF 0000
H
– 03FF 1FFF
H
1
8 KB
03FF 2000
H
– 03FF 3FFF
H
2
4 KB
03FF 4000
H
– 03FF 4FFF
H
µPD70F3424
24 KB
0
8 KB
03FF 0000
H
– 03FF 1FFF
H
1
8 KB
03FF 2000
H
– 03FF 3FFF
H
2
8 KB
03FF 4000
H
– 03FF 5FFF
H
µPD70F3425
a
a)
The µPD70F3425’s 32 KB RAM area 03FF 0000
H
to 03FF 7FFF
H
is mirrored to
the subsequent area 03FF 8000
H
to 03FF FFFF
H
. Since the upper 4 KB
03FF F000
H
to 03FF FFFF
H
is used to access the fixed peripheral I/O area, the
RAM mirror must not be used to access the RAM.
32 KB
0
16 KB
03FF 0000
H
– 03FF 3FFF
H
1
16 KB
03FF 4000
H
– 03FF 7FFF
H
µPD70F3426
µPD70F3427
60 KB
0
16 KB
03FF 0000
H
– 03FF 3FFF
H
1
16 KB
03FF 4000
H
– 03FF 7FFF
H
2
16 KB
03FF 8000
H
– 03FF BFFF
H
3
12 KB
03FF C000
H
– 03FF EFFF
H
electronic components distributor