CHAPTER 3 CPU ARCHITECTURE
Table 3-4. Special Function Register List (1/2)
Address
Special Function Register (SFR) Name
Symbol
R/W
Bit Manipulation Unit
After Reset
00H
1 Bit
8 Bits
16 Bits
FF00H
FF01H
FF02H
FF03H
FF05H
FF06H
FF07H
FF08H
FF09H
FF0CH
FF0DH
FF0EH
FF0FH
FF10H
Port 0
P0
P1
P2
P3
P5
P6
P7
P8
P9
R/W
√
√
√
√
√
√
√
√
√
−
−
−
−
−
−
−
√
√
√
√
√
√
√
√
√
√
√
√
√
√
√
√
−
−
−
−
−
−
−
−
Port 1
Port 2
Port 3
Port 5
Port 6
R
Port 7
R/W
Port 8Note 1
Port 9Note 1
−
Notes 3, 4
√
√
8-bit compare register 60
8-bit compare register 50
8-bit timer counter 60
8-bit timer counter 50
Transmit shift register 20
Receive buffer register 20
A/D conversion result register 0
CR60
CR50
TM60
TM50
CR6
W
R
Undefined
00H
Note 2
Notes 3, 4
TM6
Note 2
TXS20 SIO20
RXB20
W
R
−
FFH
−
Undefined
0000H
Notes 3
√
FF14H
FF15H
FF16H
FF17H
FF18H
FF19H
FF1AH
FF1BH
FF20H
FF21H
FF22H
FF23H
FF25H
ADCR0Note 5
R
Notes 3, 4
Notes 3, 4
Note 3
16-bit compare register 90
16-bit timer counter 90
16-bit capture register 90
CR90Note 2
TM90Note 2
TCP90Note 2
W
R
−
−
−
−
−
−
√
√
FFFFH
0000H
Undefined
FFH
√
Port mode register 0
Port mode register 1
Port mode register 2
Port mode register 3
Port mode register 5
PM0
PM1
PM2
PM3
PM5
R/W
√
√
√
√
√
√
√
√
√
√
−
−
−
−
−
Notes 1. µPD789426 and 789436 Subseries only.
2. Name of SFR dedicated for 16-bit access.
3. Only in short direct addressing, 16-bit access is possible.
4. These are 16-bit access dedicated registers, however, 8-bit access is possible. When performing 8-bit
access, access using direct addressing.
5. When used as an 8-bit A/D converter (µPD789426 and 789446 Subseries), only 8-bit access is
possible. In this case, the address is FF15H.
When used as a 10-bit A/D converter (µPD789436 and 789456 Subseries), only 16-bit access is
possible. When the µPD78F9436, a flash memory version of the µPD789425 or µPD789426, is used,
this register can be accessed in 8-bit units. However, only an object file assembled with the
µPD789425 or µPD789426 can be used. The same is also true for the µPD78F9456, a flash memory
version of the µPD789445 or µPD789446: this register can be accessed in 8-bit units, but only an
object file assembled with the µPD789445 or µPD789446 can be used.
66
User’s Manual U15075EJ1V0UM00
NEC [ NEC ]
