MPC555CME Freescale Semiconductor, MPC555CME Datasheet - Page 192

• Manufacturer Part Number: MPC555CME
• Description: KIT EVALUATION FOR MPC555
• Manufacturer: Freescale Semiconductor
• Type: Microcontrollerr

Specifications of MPC555CME

• Contents: Module Board, Installation Guide, Power Supply, Cable, Software and more
• Processor To Be Evaluated: MPC555
• Data Bus Width: 32 bit
• Interface Type: RS-232
• For Use With/related Products: MPC555
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

4.4.7 Error Detection
4.5 Exception Table Relocation
MPC555
USER’S MANUAL
The BE bit defined in
mines whether the BBC operates burst cycles or not. Burst requests are enabled only
when the BE bit is set.
If the IMPU detects access violation, the following actions must be taken:
If the required address contains show cycle or program trace attributes, than the BBC
delivers the access onto the U-bus even if the request is cancelled (due to the excep-
tion it caused).
The way the IMPU notifies the RCPU core for an interrupt is by feeding error informa-
tion into four bits (1, 3, 4 and 10) in the SRR1 register in the core. Only one bit is set
at a time. The exception vector (address) that the core issues for this event is 0xnnn0-
1300. The encoding of the status bits is as follows:
The BBC has the ability to relocate the exception table. Exception table relocation is a
feature to save memory space in the exception table. See
Table
ceptions to be separated by eight bytes instead of 256 bytes (see
location feature maps the exception table into the internal memory space of the
MPC555 / MPC556 and requries MSR[IP] = 1. This feature is important in multi-
MPC555 / MPC556 systems, where more than one MCU can have internal exception
tables with the same exception addresses issued by the RCPU.
The relocation feature also saves the wasted space between exception table entries
when each exception entry contains only a branch instruction to the exception routine,
which is located elsewhere.
If exception relocation is enabled (ETRE bit is set in the BBCMCR), all exception rou-
tines (except the reset exception routine) can be controlled to either remain in the low-
er addresses of the memory (base address + exception offset) BBCMCR[OERC] = 0
or to be relocated to memory (base address + 32 Kbytes) by setting BBCMCR[OERC]
= 1. The reset exception routine location is fixed in memory (base address + the reset
exception offset) and can not be relocated.
See
1. Cancel the request that was forwarded to the burst buffer controller
2. Inform the RCPU core that the requested address generated an exception
• SRR1 = 0
• SRR3 = Guarded storage.
• SRR4 = Protected storage.
• SRR10 = 0
4.6.4 BBC Module Configuration Register (BBCMCR)
/
MPC556
for normal operation of the exception vector table. This is done by mapping ex-
The negated state of the BE bit is useful mainly when the RCPU core
runs in serialized mode. (Refer to
Register
for the ICTRL register.)
4.6.4 BBC Module Configuration Register (BBCMCR)
Rev. 15 October 2000
BURST BUFFER
NOTE
21.7.6 I-Bus Support Control
3.11.5 Exception Vector
for programming details.
Table
4-1). The re-
MOTOROLA
deter-
4-16