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Section 8 I/O Ports
8.1
Overview
The H8S/2319 and H8S/2318 Groups have 10 I/O ports (ports 1, 2, 3, and A to G), and one input-
only port (port 4).
Table 8-1 summarizes the port functions. The pins of each port also have other functions.
Each port includes a data direction register (DDR) that controls input/output (not provided for the
input-only ports), a data register (DR) that stores output data, and a port register (PORT) used to
read the pin states.
Ports A to E have a built-in MOS pull-up 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.
Port 3 and port A include an open drain control register (ODR) that controls the on/off state of the
output buffer PMOS.
Ports 1, A to F can drive a single TTL load and 50 pF capacitive load, and ports 2, 3, and G can
drive a single TTL load and 30 pF capacitive load.
Ports 1, 2, and ports 34, 35 (only when used as IRQ inputs), ports F0 to F3 (only when used as
IRQ inputs), ports G0 and G1 (only when used as IRQ inputs) are schmitt-triggered inputs.
Rev. 5.00, 12/03, page 215 of 1088
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