h8s-2110b Renesas Electronics Corporation., h8s-2110b Datasheet - Page 160

• Manufacturer Part Number: h8s-2110b
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

Section 7 I/O Ports
P90DDR
Pin Function
Note: * When the IRQ2E bit in IER is set to 1, this pin is used as the IRQ2 input pin.
7.11
Port A is an 8-bit I/O port. Port A pins also function as keyboard buffer controller I/O pins, and
key-sense interrupt input pins. Port A input/output operates by VccB power independent from the
Vcc power. Up to 5 V can be applied to port A pins if VccB power is 5 V. Port A has the
following registers. PADDR and PAPIN have the same address.
7.11.1
PADDR specifies input or output for the pins of port A on a bit-by-bit basis.
Bit
7
6
5
4
3
2
1
0
Rev. 2.00 Mar 21, 2006 page 122 of 518
REJ09B0299-0200
P90/IRQ2
The pin function is switched as shown below according to the status of the P90DDR bit.
Port A data direction register (PADDR)
Port A output data register (PAODR)
Port A input data register (PAPIN)
Bit Name
PA7DDR
PA6DDR
PA5DDR
PA4DDR
PA3DDR
PA2DDR
PA1DDR
PA0DDR
Port A
Port A Data Direction Register (PADDR)
Initial Value
0
0
0
0
0
0
0
0
P90 input pin
W
W
W
W
W
W
W
W
R/W
0
Description
The corresponding port A pins are output ports
when PADDR bits are set to 1, and input ports
when cleared to 0.
PA7 to PA2 pins are used as the keyboard buffer
controller I/O pins by setting the KBIOE bit to 1,
while the I/O direction according to PA7DDR to
PA2DDR is ignored.
PADDR has the same address as PAPIN, if read,
port A status is returned.
IRQ2 input pin *
P90 output pin
1