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CHAPTER 3
CPU ARCHITECTURE
User’s Manual U12790EJ2V0UD
3.1.1 Internal program memory space
The internal program memory space stores programs and table data, and is usually addressed by the program
counter (PC).
The
PD178078, 178098A Subseries products incorporate the following internal ROM (or flash memory).
Table 3-1. Internal Memory Capacity
Product
Structure
Capacity
PD178076, 178078
Mask ROM
49152
× 8 bits (0000H to BFFFH)
PD178096A, 178098A
61440
× 8 bits (0000H to EFFFH)
PD178F098
Flash memory
(1) Vector table area
The 64-byte area 0000H to 003FH is reserved as a vector table area. The reset input and program start
addresses for branch upon generation of an interrupt request are stored in the vector table area. Of the 16-
bit address, the lower 8 bits are stored at even addresses and the higher 8 bits are stored at odd addresses.
Table 3-2. Vector Table
Vector Table Address
Interrupt Request
Vector Table Address
Interrupt Request
0000H
Reset input
001CH
INTTM50
0004H
INTWDT
001EH
INTTM51
0006H
INTP0
0020H
INTSER0Note 1
0008H
INTP1
0022H
INTSR0Note 1
000AH
INTP2
0024H
INTST0Note 1
000CH
INTP3
0026H
INTBTM0
000EH
INTP4
0028H
INTTM00
0010H
INTP5
002AH
INTTM01
0012H
INTP6
002CH
INTIE1Note 2
0014H
INTP7
002EH
INTIE2Note 2
0016H
INTCSI0
0030H
INTAD
0018H
INTCSI1
003EH
BRK
001AH
INTCSI3
Notes 1.
PD178076, 178078, and 178F098 only.
2.
PD178096A, 178098A, and 178F098 only.
(2) CALLT instruction table area
The 64-byte area 0040H to 007FH can store the subroutine entry address of a 1-byte call instruction (CALLT).
(3) CALLF instruction entry area
The area 0800H to 0FFFH can perform a direct subroutine call with a 2-byte call instruction (CALLF).