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MPC8349E-mITX-GP Reference Design Platform User’s Guide, Rev. 0
10
Freescale Semiconductor
Preliminary—Subject to Change Without Notice
MPC8349E-mITX-GP Board
is connected to the DDR DIMM module SPD (serial presence detect) EEPROM, the two PCF8574 I
2
C
expanders, the DS1339 RTC (real time clock).
The M24256 serial EEPROM can be used to store the reset configuration word of the MPC8349E, as well
as storing the configuration registers values if boot sequencer of MPC8349E is enabled. If user wants to
load the reset configuration word from the I2C1 M24256 EEPROM, the jumper J22 should be set to
ABCDEFGH=01011110, with 1=jumper removed and 0=jumper installed. For more details on how to
program the reset configuration word value in I
2
C EEPROM and the boot sequencer mode, please refer to
the MPC8349ERM. The I
2
C address of the M24256 EEPROM on I2C1 bus is 0x50.
The DDR SPD EEPROM is connected to the I2C2 of MPC8349E. The bootload program optionally reads
the SPD EEPROM data to determine the DDR DIMM physical structure (e.g. number of rows and
columns), the DDR timings (e.g. CAS latency, re-fresh timing), and setup the configuration registers of
the MPC8349E DDR memory controller. The I
2
C address of the DDR SPD EEPROM on I2C2 bus is 0x51.
There are two PCF8574A I
2
C I/O expander on the MPC8349E-mITX-GP board to provide general
purpose I/O expansion via the I2C2 interface. The first PCF8574A (U8) has I2C2 address 0x38 and it is
able to control the Green LED (D1) and Yellow LED (D2), set the VSC8201 to powerdown mode. The bit
definition of this PCF8574A (U8) is defined as in
Table 3
.
The second PCF8574A (U10) has I2C2 address 0x39 and it is able to detect the board revision number,
the PCI M66EN signal level and detect which Flash is currently used to boot. The bit definition of this
PCF8574A (U10) is defined as in
Table 4
.
Table 3. PCF8574A (U8) Bit Descriptions
PCF8574A (U8)
Bit[0..7]
Name
Read/Write
Description
0
LED0
Write only,
read returns 1
LED0 control
0: LED is on
1: LED is off
1
LED1
Write only,
read returns 1
LED1 control
0: LED is on
1: LED is off
2
VSC8201_PWN
Write only,
read returns 1
VSC8201 power down control
0: VSC8201 PHY is powerdown
1: VSC8201 PHY in normal mode
3
Reserved
Write only,
read returns 1
Reserved
4
LCD_EN
Write only,
read returns 1
Reserved
5
Not used
—
—
6
Not used
—
—
7
Not used
—
—