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Parallel Interface Port (PIP)
7-342
MC68360 USER’S MANUAL
BSY—Busy condition
A data byte/word was not received/transmitted by the PIP due to lack of buffers.
CHR—Character Received/Transmitted
A data character was transmitted or received. This event may be used to generate inter-
rupts to the CPU32+ core if the PIP was programmed to be controlled by host software.
BD—Rx/Tx Buffer
A complete buffer has been received/transmitted on the PIP channel. The channel closes
the receive buffer due to one of the following events:
Reception of a user-defined control character (and reject (R) = 0 for that character in
the Centronics control characters table).
Data length termination (the receive buffer was filled, or the transmit buffer has finished
transmitting).
Reception of a programmable silence period.
7.13.7.6 PIP MASK REGISTER (PIPM). The PIPM is an 8-bit read-write register. It shares
the same address as the SMC2 mask register; thus, SMC2 cannot be used simultaneously
with the PIP. Each bit in the PIPM corresponds a bit in the PIPE. If a bit in the PIPM is a one,
the corresponding interrupt in the PIPE will be enabled. If the bit is a zero, the corresponding
interrupt in the PIPE will be masked. This register is cleared at reset.
7.13.8 Centronics Controller Overview
Centronics is a parallel peripheral interface bus that is generally used as a communication
channel between a host computer and printing equipment. The interface uses an 8 bit data
bus, handshake signals that control the data exchange, and some status lines that reflect
the peripheral device status. Traditionally, the direction of data transfer is from the host com-
puter to the peripheral device. New standards, such as IEEE P1284, allow reverse channel
operation (i.e data can be transferred from the peripheral to the host.)
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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