Motorola MPC860 PowerQUICC, User Manual

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MOTOROLA Chapter 33. Parallel Interface Port 33-7
Part V. The Communications Processor Module
Table 33-5 describes the control character table, RCCM, and RCCR Þelds.
33.4 The PIP Registers
The PIP registers include one conÞguration register (PIPC), and an event register (PIPE)
with its corresponding mask register (PIPM). A timing parameters register (PTPR) allows
the user to program pulsed handshake timings. The port B registers must also be conÞgured
for PIP operation. The following subsections describe the PIP registers.
33.4.1 PIP ConÞguration Register (PIPC)
The PIP conÞguration (PIPC) register determines all PIP options. Figure 33-5 shows the
register format.
1
Offset from PIP base address. PIP base = IMMR + 0x3F80 (SMC2).
Table 33-5. Control Character Table, RCCM, and RCCR Descriptions
Offset
1
Bits Name Description
0x2CÐ
0x3A 0 E End of table. In tables with eight control characters, E is always 0.
0 This entry is valid.
1 The entry is not valid and is not used.
1 R Reject character.
0 The character is not rejected but is written into the Rx buffer, which is then
closed. A new buffer is opened if more data is in the message. A maskable
interrupt is generated.
1 If this character is recognized it is written to RCCR and not to the Rx buffer. A
maskable interrupt is generated. The current Rx buffer is not closed.
2Ð7 Ñ Reserved
8Ð15 CHARACTERn Control character values 1Ð8. DeÞnes control characters to be compared to the
incoming character. For characters smaller than 8 bits, the most signiÞcant bits
should be zero.
0x3C 0Ð1 0b11 Must be set. Used to mark the end of the control character table in case eight
characters are used. Setting these bits ensures correct operation during control
character recognition.
2Ð7 Ñ Reserved
8Ð15 RCCM Received control character mask. Used to mask the comparison of
CHARACTER
n . RCCM[8Ð15] correspond to the eight bits of CHARACTER n and
are decoded as follows.
0 Ignore this bit when comparing the incoming character to CHARACTER
n .
1 Use this bit when comparing the incoming character to CHARACTER n .
0x3E 0Ð7 Ñ Reserved
8Ð15 RCCR Received control character register. If the newly arrived character matches and is
rejected from the buffer (R = 1), the PIP controller writes the character into the
RCCR and generates a maskable interrupt. If the core does not process the
interrupt and read RCCR before a new control character arrives, the previous
control character is overwritten.