Freescale Semiconductor PowerQUICC MPC885 Reference Manual page 917

Figure 33-21 shows the PIP configured as a Centronics transmitter.
33.9.1.1 Centronics Tx Errors and the PIPE
The Centronics transmission errors are described in
Error
BD Not Ready The current BD to be processed is not ready. PIPE[TXE] is flagged. The channel continues sending
after S/W prepares the BD and sets PIPC[STR].
Printer Off-Line The printer is off-line. TxBD[S] and PIPE[TXE] are flagged. The channel resumes sending after
RESTART TRANSMIT
is controlling the transfer.
Printer Fault The printer has a fault condition. TxBD[F] and PIPE[TXE] are flagged. The channel resumes
sending after
when the CP is controlling the transfer.
Paper Error The printer has an error in its paper path. TxBD[PE] and PIPE[TXE] are flagged. The channel
resumes sending after
status line when the CP is controlling the transfer.
The relevant PIPE flags during Centronics transmission are TXE, TCH, and TXB; see
Event Register (PIPE)."
applies.
33.9.2 PIP as a Centronics Receiver
If the current BD in the RxBD table is empty and a character is received from the Centronics interface, the
PIP receiver first compares the character against the user-defined control character table. If no match is
found, the character is written to the buffer. If a match is found, the control character is either written to
the Rx buffer or rejected, depending on the reject bit in the control character table. If rejected, the character
is written to the received control character register (RCCR) in the PIP Rx parameter RAM and a maskable
Freescale Semiconductor
MPC885
(Host)
PB[16:23]
PB15
PB14
PB31
PB30
PB29
PB28
[ * ] – Optional
Figure 33-21. PIP as a Centronics Transmitter
Table 33-13. Centronics Tx Errors
. Note that SMASK[S] must be set to sense this printer status line when the CP
. Note that SMASK[F] must be set to sense this printer status line
RESTART TRANSMIT
RESTART TRANSMIT
For core-controlled transmissions, only the character-based TCH interrupt
MPC885 PowerQUICC Family Reference Manual, Rev. 2
Centronics
Device
Data[0:7]
STB
ACK
[ * ]
BUSY
[ * ]
SELECT
[ * ]
PERROR
[ * ]
FAULT
Table 33-13.
Description
. Note that SMASK[PE] must be set to sense this printer
Parallel Interface Port (PIP)
Section 33.4.2, "PIP
33-21