
MOTOROLA
Chapter 9. Error Handling
9-9
parity error bit (bit 15) in the PCI status register. This is independent of the settings in the
PCI command register. Note that for the MPC106 to recognize the assertion of SERR by
another PCI agent, bit 5 (RX_SERR_EN) of the alternate OS-visible parameter register 1
must be set.
If the MPC106 is acting as a PCI target and detects a PCI address parity error, the PCI
interface of the MPC106 sets the status bit in the PCI status register (bit 15). If bits 8 and 6
of the PCI command register are set, the MPC106 reports the address parity error by
asserting SERR to the master (two clocks after the address phase) and sets bit 14 of the PCI
status register. Also, if PICR1[MCP_EN] is set, the MPC106 reports the error to the 60x
processor by asserting MCP.
9.3.3.2 Data Parity Error
If the MPC106 is acting as a PCI master and a data parity error occurs, the MPC106 sets
bit 15 of the PCI status register. This is independent of the settings in the PCI command
register.
If the PCI command register of the MPC106 is programmed to respond to parity errors (bit
6 of the PCI command register is set) and a data parity error is detected or signaled during
a PCI bus transaction, the MPC106 sets the appropriate bits in the PCI status register (bit
15 is set, and possibly bit 8 is set, as described in the following paragraphs).
If a data parity error is detected by the MPC106 acting as the master (for example, during
a 60x processor-read-from-PCI transaction), and if bit 6 of the PCI command register is set,
the MPC106 reports the error to the PCI target by asserting PERR and by setting bit 8 of
the status register and tries to complete the transaction, if possible. Also, if
PICR1[MCP_EN] is set, the MPC106 asserts MCP to report the error to the 60x processor.
These actions also occur if the MPC106 is the master and detects the assertion of PERR by
the target (for a write).
If the MPC106 is acting as a PCI target when the data parity error occurs (on a write), the
MPC106 asserts PERR, and sets ErrDR1[6] (PCI target PERR). If the data had been
transferred, the MPC106 completes the operation but discards the data. Also, if
PICR1[MCP_EN] is set, the MPC106 asserts MCP to report the error to the 60x processor.
In the case that PERR is asserted by the master during a memory read, the address of the
transfer will be logged in the error address register and MCP is optionally asserted.
9.3.3.3 Master-Abort Transaction Termination
If the MPC106, acting as a master, initiates a PCI bus transaction (excluding special-cycle
and configuration transactions), but there is no response from any PCI agent (DEVSEL has
not been asserted within five PCI bus clocks from the start of the address phase), the
MPC106 terminates the transaction with a master-abort and sets the master-abort flag
(bit 13) in the PCI status register.