Renesas Hitachi H8S/2191, Hardware Manual

Page: 285 / 1065

Rev. 2.0, 11/00, page 258 of 1037
(4) MOS Pull-Up Select Register 3 (PUR3)
0
0
1
0
R/W
2
0
R/W
3
0
4
0
R/W
0
R/W
5
0
7
0
R/W R/W R/W R/W
6
PUR34 PUR33 PUR32 PUR31 PUR30 PUR37 PUR36 PUR35
Bit :
Initial value :
R/W :
MOS pull-up selector register 3 (PUR3) controls the ON and OFF of the MOS pull-up transistor
of port 3. Only the pin whose corresponding bit of PCR3 was set to 0 (input) becomes valid. If
the corresponding bit of PCR3 is set to 1 (output), the corresponding bit of PUR3 becomes
invalid and the MOS pull-up transistor is turned off.
PUR3 is an 8-bit read/write enable register. When reset, PUR3 is initialized to H'00.
Bit n
PCR3n Description
0 The P3n pin has no MOS pull-up transistor (Initial value)
1 The P3n pin has a MOS pull-up transistor
(n = 7 to 0)
11.5.3 Pin Functions
This section describes the port 3 pin functions and their selection methods.
(1) P37/TMO
P37/TMO is switched as shown below according to the PMR37 bit in PMR3 and the PCR37
bit in PCR3.
PMR37 PCR37 Pin Function
0 P37 input pin 0
1 P37 output pin
1
*
TMO output pin
Note: * Don't care.