h8s-2635 Renesas Electronics Corporation., h8s-2635 Datasheet - Page 283

• Manufacturer Part Number: h8s-2635
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

Section 9 I/O Ports
Section 9 I/O Ports
9.1
Overview
The chip has 10 I/O ports (ports 1, 3 and A to F, H, J), and two input-only port (ports 4 and 9).
Table 9-1 summarizes the port functions. The pins of each port also have other functions.
Each I/O port includes a data direction register (DDR) that controls input/output, a data register
(DR) that stores output data, and a port register (PORT) used to read the pin states. The input-only
ports do not have a DR or DDR register.
Ports A to E have an on-chip pull-up MOS function, and in addition to DR and DDR, have a MOS
input pull-up control register (PCR) to control the on/off state of MOS input pull-up.
Ports 3, and A to C include an open-drain control register (ODR) that controls the on/off state of
the output buffer PMOS.
When ports 10 to 13 and A to F are used as the output pins for expanded bus control signals, they
can drive one TTL load plus a 90pF capacitance load. Those ports in other cases and ports 14 to 17
and 3 can drive one TTL load and a 30pF capacitance load. All I/O ports can drive Darlington
transistors when set to output.
Port 1 pins (P16 and P14) and port 3 pins (P35 and P32) and port F (PF3 and PF0) are Schmitt-
trigger inputs.
See appendix C, I/O Port Block Diagrams, for a block diagram of each port.
Rev. 6.00 Feb 22, 2005 page 223 of 1484
REJ09B0103-0600