CHAPTER 3 CPU ARCHITECTURE
53
User’s Manual U11302EJ4V0UM
3.1.1 Internal program memory space
The internal program memory space stores programs and table data. Normally, this space is addressed using
the program counter (PC).
Each product in the
µ
PD780208 Subseries contains internal ROM (or PROM) with the capacity shown below.
Table 3-1. Internal ROM Capacity
The following areas are allocated to the internal program memory space.
(1) Vector table area
The 64-byte area 0000H to 003FH is reserved as vector table area. Program start addresses for branch upon
RESET input or interrupt request generation 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 Source
Vector Table Address
Interrupt Source
0000H
RESET input
0010H
INTCSI1
0004H
INTWDT
0012H
INTTM3
0006H
INTP0
0014H
INTTM0
0008H
INTP1
0016H
INTTM1
000AH
INTP2
0018H
INTTM2
000CH
INTP3
001AH
INTAD
000EH
INTCSI0
001CH
INTKS
003EH
BRK instruction
(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).
Internal ROM
Configuration
Mask ROM
Mask ROM
Mask ROM
Mask ROM
PROM
Capacity
32768 x 8 bits
40960 x 8 bits
49152 x 8 bits
61440 x 8 bits
61440 x 8 bits
Part Number
µ
PD780204
µ
PD780204A
µ
PD780205
µ
PD780205A
µ
PD780206
µ
PD780208
µ
PD78P0208
Содержание mPD780204
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