MOTOROLA
Chapter 2. Signal Descriptions
2-5
Signal Summary
Interrupt Controller
IRQ0 / SGPIOC0 / MDO4
1
I
MDO4 if the
Nexus (READI)
port is enabled,
IRQ0 otherwise.
Interrupt Request 0. One of the eight external signals that
can request, by means of the internal interrupt controller, a
service routine from the RCPU. IRQ0 is a non-maskable
interrupt (NMI).
I/O
Port SGPIOC0. Allows the signal to be used as a
general-purpose input/output.
O
READI Message Data Out. Message data out (MDO4) are
output signals used for uploading OTM, BTM, DTM, and
read/write accesses. External latching of MDO occurs on
rising edge of MCKO. Eight signals are implemented.
IRQ1 / RSV / SGPIOC1
1
I
IRQ1
Interrupt Request 1. One of the eight external signals that
can request, by means of the internal interrupt controller, a
service routine from the RCPU.
O
Reservation. This signal is used, together with the address
bus, to indicate that the internal core initiated a transfer as a
result of a STWCX or a LWARX instruction.
I/O
Port SGPIOC1. Allows the signal to be used as a
general-purpose input/output.
IRQ2 / CR / SGPIOC2 / MTS 2
1
I
IRQ2
Interrupt Request 2. One of the eight external signals that
can request, by means of the internal interrupt controller, a
service routine from the RCPU.
I
Cancel Reservation. Instructs the MPC561/MPC563 to clear
its reservation because some other master has touched its
reserved space. An external bus snooper asserts this signal.
I/O
Port SGPIOC2. Allows the signal to be used as a
general-purpose input/output.
O
Memory Transfer Start. This is the transfer start signal from
the MPC561’s memory controller that allows external
memory access by an external bus master.
IRQ3 / KR / RETRY /
SGPIOC3
1
I
IRQ3
Interrupt Request 3. One of the eight external signals that
can request, by means of the internal interrupt controller, a
service routine from the RCPU.
I/O
Kill Reservation. In case of a bus cycle initiated by a STWCX
instruction issued by the RCPU core to a non-local bus on
which the storage reservation has been lost, this signal is
used by the non-local bus interface to back-off the cycle.
I/O
Retry. Indicates to a master that the cycle is terminated but
should be repeated. As an input, it is driven by the external
slave to retry a cycle.
I/O
Port SGPIOC3. Allows the signal to be used as a
general-purpose input/output.
Table 2-1. MPC561/MPC563 Signal Descriptions (continued)
Signal Name
No. of
Signals
Type
Function after
Reset 1
Description