7 I/O PORTS (PPORT)
7-2
Seiko Epson Corporation
S1C31D50/D51 TECHNICAL MANUAL
(Rev. 2.00)
Pxy
PPORT
Pxy
Pxy
Peripheral I/O function 0 I/O control
Peripheral I/O function 1 I/O control
Peripheral I/O function 2 I/O control
Peripheral I/O function 3 I/O control
General-purpose
I/O control
GPIO function
I/O cell
control signal
Output signal
Input signal
PxOUTy
PxyMUX[1:0]
GPIO/
peripheral I/O
function
switching
circuit
PxOENy
PxIENy
PxPDPUy
PxRENy
PxINy
KRSTCFG[1:0]
CLKSRC[1:0]
CLKDIV[3:0]
PxSELy
Clock
generator
CPU core
System reset
controller
DBRUN
Pxy
CLK_PPORT
I/O cell
Inter
nal data
bu
s
Exist only in the ports that supports the interrupt function.
Chattering
filter
Interrupt
control circuit
Key-entry
reset control
circuit
PxCHATENy
PxEDGEy
PxIFy
PxIEy
PxINT
Key-entry
reset signal
Figure 7.1.1 PPORT Configuration
7.2 I/O Cell Structure and Functions
Figure 7.2.1 shows the I/O cell Configuration.
Pull-up/down
Control signal
Over voltage tolerant fail-safe type I/O cell
Input signal
Input control signal
Output signal
Output control signal
Analog signal
Analog control signal
Pull-up/down
Control signal
Input signal
Input control signal
Output signal
Output control signal
Analog signal
Analog control signal
Pull-up/down
control
Analog signal
control
V
DD
R
INU
/
R
IND
R
INU
/
R
IND
V
DD
V
DD
V
SS
Pxy
V
SS
Standard I/O cell
Pull-up/down
control
Analog signal
control
V
DD
V
DD
V
DD
V
DD
V
SS
Pxy
V
SS
∗
No diode is
connected at
the V
DD
side.
Figure 7.2.1 I/O Cell Configuration
Refer to “Pin Descriptions” in the “Overview” chapter for the cell type, either the over voltage tolerant fail-safe
type I/O cell or the standard I/O cell, included in each port.
7.2.1 Schmitt Input
The input functions are all configured with the Schmitt interface level. When a port is set to input disable status
(PPORTP
x
IOEN.P
x
IEN
y
bit = 0), unnecessary current is not consumed if the P
xy
pin is placed into floating status.