Renesas Hitachi H8S/2191, Hardware Manual

Page: 264 / 1065

Rev. 2.0, 11/00, page 237 of 1037
11.1.3 MOS Pull-Up Transistors
The MOS pull-up transistors in ports 1 to 3 can be switched on or off by the MOS pull-up select
registers 1 to 3 (PUR1 to PUR3) in units of bits. Settings in PUR1 to PUR3 are valid when the
pin function is set to an input by PCR1 to PCR3. If the pin function is set to an output, the MOS
pull-up transistor is turned off. Figure 11.1 shows the circuit configuration of a pin with a MOS
pull-up transistor.
When the pin whose peripheral function is used both as an alternative function is set to the
alternative output function, the MOS pull-up transistor is turned off. When the pin is set to the
alternative input function, the MOS pull-up transistor is controlled according to the PUR setting
regardless of PCR.
V
CC
PUR
LPWRM
LPWRM
PCR
PDR
PUR
PCR
PDR
: Low power consumption mode signal
(The MOS pull-up transistor is turned off in reset, standby, and
watch modes.)
: MOS pull-up select register
: Port control register
: Port data register
Input data
V
CC
V
SS
Figure 11.1 Circuit Configuration of Pin with MOS Pull-Up Transistor