I/O Memory Of Input Ports - Epson S1C63454 Technical Manual

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.
Register
Address
D3 D2
SIK03 SIK02 SIK01
FF20H
R/W
K03 K02
FF21H
R
KCP03 KCP02 KCP01 KCP00
FF22H
R/W
0 0
FFE4H
R
0 0
FFF4H
R
*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 (FF21H)
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
(V ), and "0" when the voltage goes low (V
DD
These bits are dedicated for reading, so writing cannot be done.
SIK00–SIK03: K0 port interrupt selection register (FF20H)
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.
At initial reset, these registers are set to "0".
KCP00–KCP03: K0 port input comparison register (FF22H)
Interrupt conditions for terminals K00–K03 can be set with these registers.
When "1" is written: Falling edge
When "0" is written: Rising edge
Reading: Valid
The interrupt conditions can be set for the rising or falling edge of input for each of the four bits (K00–
K03), through the input comparison registers (KCP00–KCP03).
S1C63454 TECHNICAL MANUAL
CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (Input Ports)
Table 4.4.4.1 Control bits of input ports
∗1
D1 D0 Name Init
SIK03 0
SIK00
SIK02 0
SIK01 0
SIK00 0
∗2
K03 –
K01 K00
∗2
K02 –
∗2
K01 –
∗2
K00 –
KCP03 1
KCP02 1
KCP01 1
KCP00 1
∗3 ∗2
0 –
0 EIK0
∗3 ∗2
0 –
∗3 ∗2
0 –
R/W
EIK0 0
∗3 ∗2
0 –
0 IK0
∗3 ∗2
0 –
∗3 ∗2
0 –
R/W
IK0 0
SS
1 0
Enable Disable
Enable Disable
K00–K03 interrupt selection register
Enable Disable
Enable Disable
High Low
High Low
K00–K03 input port data
High Low
High Low
K00–K03 input comparison register
Unused
Unused
Unused
Enable Mask Interrupt mask register (K00–K03)
(R) (R)
Unused
Yes No
Unused
(W) (W) Unused
Reset Invalid
Interrupt factor flag (K00–K03)
).
EPSON
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