Datasheet

Section 20 Synchronous Serial Communication Unit (SSU)
Page 1120 of 1408 R01UH0309EJ0500 Rev. 5.00
Sep 24, 2012
H8S/2456, H8S/2456R, H8S/2454 Group
20.4.4 Communication Modes and Pin Functions
The SSU switches the input/output pin (SSI, SSO, SSCK, and SCS) functions according to the
communication modes and register settings. When a pin is used as an input pin, clear the
corresponding bit in each data direction register (DDR) to 0. The relationship of communication
modes and input/output pin functions are shown in tables 20.4 to 20.6.
Table 20.4 Communication Modes and Pin States of SSI and SSO Pins
Register Setting Pin State
Communication
Mode
SSUMS BIDE MSS TE RE SSI SSO
0 0 0 0 1 ⎯ Input SSU communication
mode
1 0 Output ⎯
1 Output Input
1 0 1 Input ⎯
1 0 ⎯ Output
1 Input Output
0 1 0 0 1 ⎯ Input SSU (bidirectional)
communication mode
1 0 ⎯ Output
1 0 1 ⎯ Input
1 0 ⎯ Output
1 0 0 0 1 Input ⎯ Clock synchronous
communication mode
1 0 ⎯ Output
1 Input Output
1 0 1 Input ⎯
1 0 ⎯ Output
1 Input Output
[Legend]
⎯: Not used as SSU pin (can be used as I/O port)