Internal Program Memory Space - NEC mPD780024AS Series Preliminary User's Manual

3.1.1 Internal program memory space

The internal program memory space contains the program and table data. Normally, it is addressed with the
program counter (PC).
The µ PD780024AS, 780034AS Subseries products incorporate an on-chip ROM (or flash memory), as listed below.
µ PD780021AS, 780031AS
µ PD780022AS, 780032AS
µ PD780023AS, 780033AS
µ PD780024AS, 780034AS
µ PD78F0034BS
The internal program memory space is divided into the following three areas.
(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 each interrupt request are stored in the vector table area. Of the 16-
bit address, lower 8 bits are stored at even addresses and higher 8 bits are stored at odd addresses.
Vector Table Address
0000H
0004H
0006H
0008H
000AH
000CH
000EH
0010H
0012H
0014H
(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).
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CHAPTER 3 CPU ARCHITECTURE
Table 3-1. Internal ROM Capacity
Part Number
Table 3-2. Vector Table
Interrupt Source
RESET input
INTWDT
INTP0
INTP1
INTP2
INTP3
INTSER0
INTSR0
INTST0
INTCSI30
Preliminary User's Manual U16035EJ1V0UM
Type
8192 × 8 bits (0000H to 1FFFH)
Mask ROM
16384 × 8 bits (0000H to 3FFFH)
24576 × 8 bits (0000H to 5FFFH)
32768 × 8 bits (0000H to 7FFFH)
32768 × 8 bits (0000H to 7FFFH)
Flash memory
Vector Table Address
0016H
001AH
001CH
001EH
0020H
0022H
0024H
0026H
0028H
003EH
Capacity
Interrupt Source
INTCSI31
INTWTI
INTTM00
INTTM01
INTTM50
INTTM51
INTAD0
INTWT
INTKR
BRK