NEC PD78F9488 - Manual (Page 52)

CHAPTER 3 CPU ARCHITECTURE
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User’s Manual U15331EJ4V1UD
3.1.1 Internal program memory space
The internal program memory space stores programs and table data. This space is usually addressed by the
program counter (PC).
The µPD789489 Subseries provide internal ROM (or flash memory) with the following capacity for each product.
Table 3-1. Internal ROM Capacity
Part Number Internal ROM
Structure Capacity
µ PD789488 Mask ROM
µ PD78F9488 Flash memory
32768 × 8 bits
µ PD789489 Mask ROM
µ PD78F9489 Flash memory
49152 × 8 bits
The following areas are allocated to the internal program memory space.
(1) Vector table area
The 46-byte area of addresses 0000H to 002DH is reserved in the µPD789488 and 78F9488, and the 48-
byte area of address 0000H to 002FH is reserved in the µPD789489 and 78F9489 as a vector table area.
This area stores program start addresses to be used when branching by RESET input or interrupt request
generation. Of a 16-bit program address, the lower 8 bits are stored in an even address, and the higher 8
bits are stored in an odd address.
Table 3-2. Vector Table
Vector Table Address Interrupt Request Vector Table Address Interrupt Request
0000H RESET input 0018H INTTM20
0004H INTWDT 001AH INTTM50
0006H INTP0 001CH INTTM60
0008H INTP1 001EH INTTM61
000AH INTP2 0020H INTAD0
000CH INTP3 0022H INTWT
000EH INTRIN Note 0024H INTKR00
0010H INTSR20/INTCSI20 0026H INTRERR Note
0012H INTCSI10 0028H INTGP Note
0014H INTST20 002AH INTREND Note
0016H INTWTI 002CH INTDFULL Note
002EH INTKR01 Note
Note µPD789489 and 78F9489 only. There are no interrupt requests corresponding to vector table
addresses 000EH, and 0026H through 002EH for
µPD789488 and 78F9488.
(2) CALLT instruction table area
The subroutine entry address of a 1-byte call instruction (CALLT) can be stored in the 64-byte area of
addresses 0040H to 007FH.