MC68331
USER’S MANUAL
REGISTER SUMMARY
MOTOROLA
D-35
D
LOOPQ — QSPI Loop Mode
0 = Feedback path disabled
1 = Feedback path enabled
HMIE — HALTA and MODF Interrupt Enable
0 = HALTA and MODF interrupts disabled
1 = HALTA and MODF interrupts enabled
HALT — Halt
0 = Halt not enabled
1 = Halt enabled
SPIF — QSPI Finished Flag
0 = QSPI not finished
1 = QSPI finished
MODF — Mode Fault Flag
0 =Normal operation
1 =Another SPI node requested to become the network SPI master while the QSPI
was enabled in master mode (SS input taken low).
HALTA — Halt Acknowledge Flag
0 = QSPI not halted
1 = QSPI halted
CPTQP — Completed Queue Pointer
CPTQP points to the last command executed. It is updated when the current command
is complete. When the first command in a queue is executing, CPTQP contains either
the reset value ($0) or a pointer to the last command completed in the previous queue.
D.4.14 RR[0:F]
— Receive Data RAM
Data received by the QSPI is stored in this segment. The CPU32 reads this segment
to retrieve data from the QSPI. Data stored in receive RAM is right-justified. Unused
bits in a receive queue entry are set to zero by the QSPI upon completion of the indi-
vidual queue entry. The CPU can access the data using byte, word, or long-word ad-
dressing.
$YFFD00–$YFFD0E
D.4.15 TR[0:F]
— Transmit Data RAM
Data that is to be transmitted by the QSPI is stored in this segment. The CPU32 nor-
mally writes one word of data into this segment for each queue command to be exe-
cuted.
$YFFD20–$YFFD3E
Information to be transmitted must be written to transmit data RAM in a right-justified
format. The QSPI cannot modify information in the transmit data RAM. The QSPI cop-
ies the information to its data serializer for transmission. Information remains in trans-
mit RAM until overwritten.