12 i/O PORTS
S1C63003/004/008/016 TeChniCal Manual
Seiko epson Corporation
12-5
(Rev. 1.1)
When the interrupt mask register (EIKxx) is set to "0," the interrupt request is masked and no interrupt is generated
to the CPU.
The key input interrupt circuit has a noise rejector to avoid unnecessary interrupt generation due to noise or chattering.
This noise rejector allows selection of a noise-reject frequency from among three types shown in Table 12.6.1. Use the
NRSP0[1:0] register for P00–P03 ports or NRSP1[1:0] register for P10–P13 ports to select a noise-reject frequency.
If a pulse shorter than the selected width is input to the port, an interrupt is not generated. When high speed response
is required, turns the noise rejecter off (bypassed).
6.1 Setting up noise rejector
Table 12.
NRSP0[1:0]/NRSP1[1:0]
Noise reject frequency
Reject pulse width
3
f
OSC1
/ 256 (128 Hz)
7.8 msec
2
f
OSC1
/ 64 (512 Hz)
2.0 msec
1
f
OSC1
/ 16 (2 kHz)
0.5 msec
0
Off (bypassed)
–
Notes: • Be sure to turn the noise rejector off before executing the SLP instruction.
• Reactivating from SLEEP status can only be done by generation of a key input interrupt factor.
Therefore when using the SLEEP function, it is necessary to set the interrupt select register
(SIPxx = "1") of the port to be used for releasing SLEEP status before executing the SLP instruc-
tion. Furthermore, enable the key input interrupt using the corresponding interrupt mask register
(EIKxx = "1") before executing the SLP instruction to run key input interrupt handler routine after
SLEEP status is released.
i/O memory of i/O ports
12.7
Table 12.7.1 shows the I/O addresses and the control bits for the I/O ports.
7.1 Control bits of I/O ports
Table 12.
Address
Register name R/W Default
Setting/data
Function
FF11H D3
nRSP11 (
*
6)
R/W
0
3 f
1
/256
1 f
1
/16
P1 key input interrupt noise reject frequency
selection (f
1
= f
OSC1
)
D2
nRSP10 (
*
6)
R/W
0
2 f
1
/64
0 Off
D1
nRSP01
R/W
0
3 f
1
/256
1 f
1
/16
P0 key input interrupt noise reject frequency
selection (f
1
= f
OSC1
)
D0
nRSP00
R/W
0
2 f
1
/64
0 Off
FF20H D3
P03
R/W
1
1 High
0 Low
P03 I/O port data
D2
P02
R/W
1
1 High
0 Low
P02 I/O port data
D1
P01
R/W
1
1 High
0 Low
P01 I/O port data
D0
P00
R/W
1
1 High
0 Low
P00 I/O port data
FF21H D3
iOC03
R/W
0
1 Output
0 Input
P03 I/O control register
D2
iOC02
R/W
0
1 Output
0 Input
P02 I/O control register
D1
iOC01
R/W
0
1 Output
0 Input
P01 I/O control register
D0
iOC00
R/W
0
1 Output
0 Input
P00 I/O control register
FF22H D3
Pul03
R/W
1
1 Enable
0 Disable
P03 pull-down control register
D2
Pul02
R/W
1
1 Enable
0 Disable
P02 pull-down control register
D1
Pul01
R/W
1
1 Enable
0 Disable
P01 pull-down control register
D0
Pul00
R/W
1
1 Enable
0 Disable
P00 pull-down control register
FF23H D3
SMT03
R/W
1
1 Schmitt
0 CMOS
P03 input I/F level select register
D2
SMT02
R/W
1
1 Schmitt
0 CMOS
P02 input I/F level select register
D1
SMT01
R/W
1
1 Schmitt
0 CMOS
P01 input I/F level select register
D0
SMT00
R/W
1
1 Schmitt
0 CMOS
P00 input I/F level select register
FF24H D3
P13
R/W
1
1 High
0 Low
P13 I/O port data
D2
P12
R/W
1
1 High
0 Low
P12 I/O port data
D1
P11
R/W
1
1 High
0 Low
P11 I/O port data
D0
P10
R/W
1
1 High
0 Low
P10 I/O port data
FF25H D3
iOC13
R/W
0
1 Output
0 Input
P13 I/O control register
D2
iOC12
R/W
0
1 Output
0 Input
P12 I/O control register
D1
iOC11
R/W
0
1 Output
0 Input
P11 I/O control register
D0
iOC10
R/W
0
1 Output
0 Input
P10 I/O control register