UPD78323 NEC, UPD78323 Datasheet - Page 22

• Manufacturer Part Number: UPD78323
• Description: 16/8-BIT SINGLE-CHIP MICROCONTROLLER
• Manufacturer: NEC

22
(4) CPU control word (CCW)
be controlled by the software.
The 8002H to 807FH address of the external memory area in place of 0002H to 007FH address can be used as each table
area by setting TPF to 1 using the software. The vector tables of the BRK instruction, operation code trap interrupt and reset
input are fixed to 003EH, 003CH and 0000H, respectively, and they are not affected by TPF.
2.2.2
of eight register banks. The general register in the bank consists of sixteen 8-bit registers.
This is an 8-bit register consisting of CPU control related flags. It is mapped in the special function register area and can
All bits are reset to 0 by RESET input.
• Table position flag (TPF)
This flag is used to specify the interrupt vector table area and the memory area used as CALLT instruction table area.
As TPF has been reset to 0 after application of RESET input, the 0000H to 007FH address is used as each table area.
These are 128-byte registers mapped in the special area (FE80H to FEFFH) of the internal RAM space. They consist
General Registers
FEFFH
FE80H
RBNK0
RBNK1
RBNK2
RBNK3
RBNK4
RBNK5
RBNK6
RBNK7
Figure 2-5. General Register Memory Location
7
0
6
0
Figure 2-4. CCW Format
5
0
7
8-Bit Processing
R15
R13
R11
R9
R7
R5
R3
R1
4
0
0 7
R14
R12
R10
R8
R6
R4
R2
R0
3
0
0
2
0
TPF
1
0
0
15
16-Bit Processing
(FH)
(DH)
(BH)
(9H)
(7H)
(5H)
(3H)
(1H)
CCW
RP7
RP6
RP5
RP4
RP3
RP2
RP1
RP0
PD78323, 78324
(EH)
(CH)
(AH)
(8H)
(6H)
(4H)
(2H)
(0H)
0