MPC8349E-mITX-GP Reference Design Platform User’s Guide, Rev. 0
Freescale Semiconductor
21
Preliminary—Subject to Change Without Notice
MPC8349E-mITX-GP Board
1.6.3
PCI Operating Frequency
An M66EN input pin determines the AC timing of the PCI interface. On the MPC8349E-mITX-GP board,
the state of this signal can be driven to 0 by the J22 jumper to select 33 MHz AC timing. If J22.F is not
driven to 0, the M66EN signal level is determined by the PCI agent card connected to PCI slot P1. If a 33
MHz only card is inserted, the M66EN signal is driven to 0 by the PCI agent card according to the PCI
specification, or it is driven to 1 if it can perform at 66 MHz. See
Table 12
.
.
1.6.4
Reset Configuration Word
The reset configuration word (RCW) controls the clock ratios and other basic device functions such as PCI
host or agent mode, boot location, TSEC modes, and endian mode. The reset configuration word is divided
into reset configuration word lower (RCWL) and reset configuration word higher (RCWH) and is loaded
from the local bus during the power-on or hard reset flow. The default RCW low bit setting is
0x0404_0000. The default RCW high bit setting is 0xB460_A000.
The RCW is located at the lowest 64 bytes of the boot Flash memory, which is 0xFE00_0000 if the default
memory map is used.
Table 11. EEPROM Write Protect
J22.G
Description
Jumper Off
Serial EEPROM is write protected (WC not asserted).
Jumper On
Serial EEPROM is not write protected (WC asserted).
Table 12. M66EN Signal Status Selection
J22.F
Description
Jumper Off
M66EN signal is determined by the card plugged into the PCI slot.
Jumper On
M66EN signal is hardwired to 0, which is hard coded to 33 MHz PCI operation.
Table 13. Default RCW in Flash Memory
Address
FE000000:
04040404
04040404
04040404
04040404
FE000010:
00000000
00000000
00000000
00000000
FE000020:
B0B0B0B0
B0B0B0B0
60606060
60606060
FE000030:
A0A0A0A0
A0A0A0A0
00000000
00000000