Chapter 3
Register Map and Descriptions
3-4
©
National Instruments Corporation
Serial Command Register
The Serial Command Register contains six bits that control PCI E Series serial EEPROM and
DACs. The contents of this register are cleared upon power up and after a reset condition.
Address:
Base a 0D (hex)
Type:
Write-only
Word Size:
8-bit
Bit Map:
Bit
Name
Description
7–6
Reserved
Reserved—Always write 0 to these bits.
5
SerDacLd2
Serial DAC Load2—This bit is used to load the third set of
serial DACs with the serial data previously shifted into the
DACs.
4
SerDacLd1
Serial DAC Load1—This bit is used to load the second set
of serial DACs with the serial data previously shifted into
the DACs.
3
SerDacLd0
Serial DAC Load0—This bit is used to load the first set of
serial DACs with the serial data previously shifted into the
DACs.
2
EEPromCS
EEPROM Chip Select—This bit controls the chip select of
the onboard EEPROM used to store calibration constants.
When EEPromCS is set, the chip select signal to the
EEPROM is enabled.
1
SerData
Serial Data—This bit is the data for the onboard serial
devices—the calibration EEPROM and the serial DACs.
This bit should be set to the desired value prior to the
active write to the SerClk bit.
0
SerClk
Serial Clock—This bit is the clock input to the onboard
serial devices. In order to access these devices, this bit is
used to clock data in or out as appropriate. See Chapter 5,
, for more information.
7
6
5
4
3
2
1
0
Reserved
Reserved
SerDacLd2
SerDacLd1
SerDacLd0
EEPromCS
SerData
SerClk