SH7144 Datasheet, PDF (378/773 Pages) Renesas Technology Corp – Hitachi SuperH RISC engine

11.9 Port Output Enable (POE)
The port output enable (POE) can be used to establish a high-impedance state for high-current
pins, by changing the POE0 to POE3 pin input, depending on the output status of the high-current
pins (PE9/TIOC3B/SCK3/TRST*, PE11/TIOC3D/RXD3/TDO*, PE12/TIOC4A/TXD3/TCK*,
PE13/TIOC4B/MRES, PE14/TIOC4C/DACK0, PE15/TIOC4D/DACK1/IRQOUT). It can also
simultaneously generate interrupt requests.
The high-current pins can also be set to high-impedance regardless of whether these pin functions
are selected in cases such as when the oscillator stops or in software standby mode. For details,
refer to section 17.1.11, High-Current Port Control Register (PPCR).
However, when using the E10A, the high-impedance function is disabled when an oscillation stop
is detected, port output enable (POE), or in the software standby state for the three pins of
PE9/TIOC3B/SCK3/TRST, PE11/TIOC3D/RXD3/TDO, and PE12/TIOC4A/TXD3/TCK of the
SH7145.
Note: * Only in the SH7145.
11.9.1 Features
• Each of the POE0 to POE3 input pins can be set for falling edge, Pφ/8 × 16, Pφ/16 × 16, or
Pφ/128 × 16 low-level sampling.
• High-current pins can be set to high-impedance state by POE0 to POE3 pin falling-edge or
low-level sampling.
• High-current pins can be set to high-impedance state when the high-current pin output levels
are compared and simultaneous low-level output continues for one cycle or more.
• Interrupts can be generated by input-level sampling or output-level comparison results.
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