D17133CS datasheet(40/289 Pages) NEC

40 / 289 page

CHAPTER 4

PROGRAM MEMORY (ROM)

Table 4-1. Vector Address for the

µPD17120 Subseries

Vector Address

Interrupt Sources

0000H

Reset

0001H

Serial interface interrupt

0002H

Timer interrupt

0003H

External interrupt (INT pin)

(2) Direct branch

When executing a direct branch (BR addr), the 11-bit instruction operand is used to specify an address in

program memory. (However, the most significant bit must be 0. If an address is specified outside of this

range, an error will occur in the assembler.) A direct branch instruction can be used to branch to any address

in program memory.

(3) Indirect branch

When executing an indirect branch (BR @AR), the program branches to the address specified by the value

stored in the address register (AR). An indirect branch can be used to branch to any address in program

memory.

Also refer to 7.2 ADDRESS REGISTER (AR).

(4) Direct subroutine call

When using a direct subroutine call (CALL addr), the 11-bit instruction operand is used to specify a program

memory address of the called subroutine. (However, the most significant bit must be 0. If an address is

specified outside of this range, an error will occur in the assembler).

D17133CS Datasheet(PDF) 40 Page - NEC