NEC 78014Y Series, User Manual

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CHAPTER 5 CPU ARCHITECTURE
100
5.1.1 Internal program memory space
Internal program memory store programs and table data. Normally, they are addressed with a program counter
(PC).
The
µ
PD78014 and 78014Y Subseries contain internal ROM (or PROM) in each product having the capacities
shown below.
Table 5-1. Internal ROM Capacity
Part Number Internal ROM
Configuration Capacity
µ
PD78011B, 78011BY Mask ROM 8192
×
8 bits
µ
PD78012B, 78012BY 16384
×
8 bits
µ
PD78013, 78013Y 24576
×
8 bits
µ
PD78014, 78014Y 32768
×
8 bits
µ
PD78P014, 78P014Y PROM
The following areas are allocated in the internal program memory space.
(1) Vector table area
The 64-byte area 0000H to 003FH is reserved as 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, the low-order 8 bits are stored at even addresses and the high-order 8 bits are stored at odd
addresses.
Table 5-2. 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 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).