37C957FR Datasheet, PDF (251/328 Pages) SMSC Corporation – ULTRA I/O CONTROLLER FOR PORTABLE APPLICATIONS

PS/2 Port transmit regsiter 1 and 2:
D7 D6 D5 D4 D3 D2 D1 D0
R/W W W W W W W W W
Data written to the PS/2 Port1/Port2 Transmit register is immediately transmitted onto the enabled
PS/2 Port 1/[Port2] port provided that the PS/2 Port1/[Port2] Inhibit bit is not set and that both PS/2
Port1/[Port2] devices are not enabled for transmit at the same time.
PS/2 Port receive register 1 and 2:
D7 D6 D5 D4 D3 D2 D1 D0
RR R R R R RRR
If KB_EN, and/or EM_EN is set and PS/2 Port1 RX_EN is set any successfully received characters
over the KB and/or the EM PS/2 Port are placed into this register and the EM_drdy or KB_drdy PS/2
Port1 status bit is set. Similarly, if PS2_EN and/or IM_EN is set and PS/2 Port2 RX_EN is set any
successfully received characters over the PS2 and/or IM PS2 Ports are placed into this register and
the PS2_drdy or IM_drdy PS/2 Port2 status bit is set.
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