Specifications
S1C60N04 TECHNICAL MANUAL EPSON 31
CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (Interrupt and HALT/SLEEP)
4.8.3 Interrupt vectors
When an interrupt request is input to the CPU, the CPU starts interrupt processing. After the program
being executed is suspended, interrupt processing is executed in the following order:
➀ The address data (value of the program counter) of the program step to be executed next is saved on
the stack (RAM).
➁ The interrupt request causes the value of the interrupt vector (page 1, 01H–07H) to be loaded into the
program counter.
➂ The program at the specified address is executed (execution of interrupt processing routine).
Note: The processing in steps 1 and 2, above, takes 12 cycles of the CPU system clock.
Table 4.8.3.1 Interrupt vector addresses
Page
1
Step
00H
01H
04H
05H
Interrupt vector
Initial reset
Clock timer interrupt
Input (K00–K03) interrupt
Clock timer & Input (K00–K03) interrupt
4.8.4 I/O memory of interrupt
Table 4.8.4.1 shows the interrupt control bits and their addresses.
Table 4.8.4.1 Control bits of interrupt
Address Comment
D3 D2
Register
D1 D0 Name Init
∗1
10
0E8H
EIK03 EIK02 EIK01 EIK00
R/W
EIK03
EIK02
EIK01
EIK00
0
0
0
0
Enable
Enable
Enable
Enable
Mask
Mask
Mask
Mask
Interrupt mask register (K03)
Interrupt mask register (K02)
Interrupt mask register (K01)
Interrupt mask register (K00)
0EBH
0 EIT2 EIT8 EIT32
RR/W
0
∗
3
EIT2
EIT8
EIT32
–
∗
2
0
0
0
–
Enable
Enable
Enable
–
Mask
Mask
Mask
Unused
Interrupt mask register (clock timer 2 Hz)
Interrupt mask register (clock timer 8 Hz)
Interrupt mask register (clock timer 32 Hz)
0EDH
000IK0
R
0
∗
3
0
∗
3
0
∗
3
IK0
∗
4
–
∗
2
–
∗
2
–
∗
2
0
–
–
–
Yes
–
–
–
No
Unused
Unused
Unused
Interrupt factor flag (K00–K03)
0EFH
0 IT2 IT8 IT32
R
0
∗
3
IT2
∗
4
IT8
∗
4
IT32
∗
4
–
∗
2
0
0
0
–
Yes
Yes
Yes
–
No
No
No
Unused
Interrupt factor flag (clock timer 2 Hz)
Interrupt factor flag (clock timer 8 Hz)
Interrupt factor flag (clock timer 32 Hz)
∗1
∗2
Initial value at initial reset
Not set in the circuit
∗3
∗4
Always "0" being read
Reset (0) immediately after being read
EIT32, EIT8, EIT2: Interrupt mask registers (0EBH•D0–D2)
IT32, IT8, IT2: Interrupt factor flags (0EFH•D0–D2)
...See Section 4.7, "Clock Timer".
EIK00–EIK03: Interrupt mask registers (0E8H)
IK0: Interrupt factor flag (0EDH•D0)
...See Section 4.3, "Input Ports".