CHAPTER 1: CONFIGURATION
II-3
Interrupt Vectors
When an interrupt request is received by the CPU, the CPU
initiates the following interrupt processing after completing
the instruction being executed.
(1) The address of the next instruction to be executed (the
value of the program counter) is saved on the stack
(RAM).
(2) The interrupt vector address corresponding to the inter-
rupt request is loaded into the program counter.
(3) The branch instruction written in the vector is executed
to branch to the software interrupt processing routine.
Steps 1 and 2 require 12 cycles of the CPU system clock.
The interrupt vectors are shown in Table 1.3.1.
1.3
Note
Table 1.3.1
Interrupt requests and vectors
Addesses (start address of interrupt processing routines) to
jump to are written into the addresses available for interrupt
vector allocation.
Step
Interrupt Vector
Initial reset
Clock timer interrupt
Input (K00–K03) interrupt
Input interrupt and clock timer interrupt
Page
00H
01H
04H
05H
1