
S1C63406/408 TECHNICAL MANUAL
EPSON
33
CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (Input Ports)
4.4.4 I/O memory of input ports
Table 4.4.4.1 shows the I/O addresses and the control bits for the input ports.
Table 4.4.4.1 Control bits of input ports
Address
Comment
D3
D2
Register
D1
D0
Name
Init 1
10
FF42H
K03
K02
K01
K00
R
K03
K02
K01
K00
– 2
High
Low
K00–K03 input port data
FF43H
00
K0NR1
K0NR0
RR/W
0 3
K0NR1
K0NR0
– 2
0
Unused
K0 interrupt
noise rejector
0
Off
1
0.5ms
2
2.0ms
3
7.8ms
[K0NR1, 0]
NR
FF54H
SIK03
SIK02
SIK01
SIK00
R/W
SIK03
SIK02
SIK01
SIK00
0
Enable
Disable
K00–K03 interrupt selection register
FF55H
KCP03
KCP02
KCP01
KCP00
R/W
KCP03
KCP02
KCP01
KCP00
1
K00–K03 input comparison register
FFEBH
EIK03
EIK02
EIK01
EIK00
R/W
EIK03
EIK02
EIK01
EIK00
0
Enable
Mask
Interrupt mask register (K03)
Interrupt mask register (K02)
Interrupt mask register (K01)
Interrupt mask register (K00)
FFFBH
IK03
IK02
IK01
IK00
R/W
IK03
IK02
IK01
IK00
0
(R)
Yes
(W)
Reset
(R)
No
(W)
Invalid
Interrupt factor flag (K03)
Interrupt factor flag (K02)
Interrupt factor flag (K01)
Interrupt factor flag (K00)
*1 Initial value at initial reset
*2 Not set in the circuit
*3 Constantly "0" when being read
K00–K03: K0 port input port data (FF42H)
Input data of the input port terminals can be read with these registers.
When "1" is read: High level
When "0" is read: Low level
Writing: Invalid
The reading is "1" when the terminal voltage of the four bits of the input ports (K00–K03) goes high
(VDD), and "0" when the voltage goes low (VSS).
These bits are dedicated for reading, so writing cannot be done.
SIK00–SIK03: K0 port interrupt selection register (FF54H)
Selects the ports to be used for the K00–K03 input interrupts.
When "1" is written: Enable
When "0" is written: Disable
Reading: Valid
Enables the interrupt for the input ports (K00–K03) for which "1" has been written into the interrupt
selection registers (SIK00–SIK03). The input port set for "0" does not affect the interrupt generation
condition.
Reactivating from SLEEP status can only be done by generation of an input interrupt factor. Therefore
when using the SLEEP function, it is necessary to set the interrupt selection register (SIK0x = "1") of the
port to be used for releasing SLEEP status before executing the SLP instruction.
At initial reset, these registers are set to "0".