NEC mPD780852 Series, Preliminary User'S Manual

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CHAPTER 3 CPU ARCHITECTURE
Preliminary User’s Manual U14581EJ3V0UM00
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
PD780852 Subseries incorporate internal ROM (or flash memory), as listed below.
Table 3-1. Internal Memory Capacity
Part Number Internal ROM
Type Capacity
µ
PD780851(A) Mask ROM 32,768
×
8 bits (0000H to 7FFFH)
µ
PD780852(A) 40,960
×
8 bits (0000H to 9FFFH)
µ
PD78F0852 Flash Memory 40,960
×
8 bits (0000H to 9FFFH)
The following three areas are allocated to the program memory space.
(1) Vector table area
The 64-byte area 0000H to 003FH is reserved as a vector table area. This area stores program start addresses
to which execution branches when the RESET signal is input or when an interrupt request is generated.
Of a 16-bit address, the lower 8 bits are stored at an even address and the higher 8 bits are stored at an odd
address.
Table 3-2. Vector Table
Vector Table Address Interrupt Source
0000H RESET input
0004H INTWDT
0006H INTAD
0008H INTOVF
000AH INTTM00
000CH INTTM01
000EH INTTM02
0010H INTP0
0012H INTP1
0014H INTP2
0016H INTCSI3
0018H INTSER
001AH INTSR
001CH INTST
001EH INTTM1
0020H INTTM2
0022H INTTM3
0024H INTCSI2
0026H INTWTI
0028H INTWT
003EH BRK