IBM nec pd78082 User Manual

The internal program memory is mask ROM with a 8192 

×

 8-bit configuration in the 

µ

PD78081, and a 16384 

×

8-bit configuration in the 

µ

PD78082, and PROM with a 24576 

×

 8-bit configuration in the 

µ

PD78P083.

The internal program memory space

 

stores programs and table data.  Normally, they are addressed with a program

counter (PC).

The internal program memory is divided into the following three areas.

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, low-order 8 bits are stored at even addresses and high-order 8 bits are stored at odd addresses.

Vector Table Address

Interrupt Request

0000H

RESET input

0004H

INTWDT

0008H

INTP1

000AH

INTP2

000CH

INTP3

0018H

INTSER

001AH

INTSR/INTCSI2

001CH

INTST

0028H

INTAD

002AH

INTTM5

002CH

INTTM6

003EH

BRK

The 64-byte area 0040H to 007FH can store the subroutine entry address of a 1-byte call instruction (CALLT).

The area 0800H to 0FFFH can perform a direct subroutine call with a 2-byte call instruction (CALLF).