Freescale Semiconductor MPC8272ADS User Manual page 48

Reset and Reset Configuration
can be taken from the E2PROM/BCSR in case the Flash has been tampered with. The
selection between the BCSR, FLASH and the E2PROM as the source of the default
configuration word is determined by a dedicated dip-switch and a jumper.
During hard reset sequence, the configuration master
BCSR) memory at addresses 0, 8, 0x18, 0x20,... a byte each time, to assemble the 32 bit
configuration word. A total of 64 bytes of data is read from D(0:7) to acquire 8 full
configuration words for system that may have up to 8 MPC8272 chips.
The configuration word for a single
2
the E PROM or as default in the BCSR, while the other seven words are not initialized, as
there are no additional MPC8272 on the MPC8272ADS. The default configuration word is
shown in Table 5-1 for the FLASH and in Table 5-2 for the E
configuration is 256 Bytes long and should start at address 0x100.
The two possible configuration words are the following:
• FLASH/BCSR is the boot device. CS0 is assigned to the FLASH and CS4 is
assigned to the E
2
• E PROM is the boot device. CS0 is assigned to the E
to the FLASH.
.
Table 5-1. BCSR/FLASH Hard Reset Configuration Word
Data
Field Bus
Bits
ERB 0
EXMC 1
CDIS 2
EBM 3
BPS 4:5
CIP 6
ISPS 7
1
MPC8272
In general, The
MPC8272
the residing on the MPC8272ADS.
2
MPC8272
Although the
word is influential.
2
MPC8272 is stored in the Flash memory SIMM, in
2
PROM.
Prog
Value
[Bin]
'0' Internal Arbitration Selected.
'0' Internal Memory Controller. CS0 active at
system boot.
'0' Core Enabled.
'0' '0' - Single PowerQUICC II Mode
11 32 Bit Boot Port Size
'0' Sets Core Initial Prefix MSR[IP]=1, so that
system exception table is placed at address
0xFFF00100 regardless of FLASH memory
size
'0' 64-bit internal space for external master
accesses. In fact don't care on this board since
external master is not supported.
for which RSTCONF is asserted along with PORST asserted or in particular,
as configuration master reads 8 configuration words, only the 1'st configuration
MPC8272ADS User Guide
1
reads the Flash (or E
2
PROM and CS4 is assigned
Implication
2
PROM or
2
PROM. PCI module
Offset In
Value
Flash
[Hex]
[Hex]
0 0C