HD64F3644PV Datasheet, PDF (201/551 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

Section 8 I/O Ports
8.3.3 Pin Functions
Table 8.6 shows the port 2 pin functions.
Table 8.6
Pin
P22/TXD
Port 2 Pin Functions
Pin Functions and Selection Method
The pin function depends on bit TXD in PMR7 and bit PCR22 in PCR2.
TXD
0
1
PCR22
Pin function
0
1
P22 input pin P22 output pin
*
TXD output pin
P21/RXD
The pin function depends on bit RE in SCR3 and bit PCR21 in PCR2.
RE
0
1
PCR21
0
1
*
Pin function
P21 input pin P21 output pin
RXD input pin
P20/SCK3
The pin function depends on bits CKE1 and CKE0 in SCR3, bit COM in SMR,
and bit PCR20 in PCR2.
CKE1
0
1
CKE0
0
1
*
COM
0
1
*
*
PCR20
0
1
*
*
Pin function
P20 input pin P20 output pin SCK3 output SCK3 input pin
pin
Legend: * Don’t care
8.3.4 Pin States
Table 8.7 shows the port 2 pin states in each operating mode.
Table 8.7
Pins
P22/TXD
P21/RXD
P20/SCK3
Port 2 Pin States
Reset
High-
impedance
Sleep
Retains
previous
state
Subsleep
Retains
previous
state
Standby
High-
impedance
Watch Subactive Active
Retains Functional Functional
previous
state
Rev. 6.00 Sep 12, 2006 page 179 of 526
REJ09B0326-0600