Specifications

Programmers Model
ARM DUI 0447J Copyright © 2009-2014, ARM. All rights reserved. 4-21
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4.4.14 System Configuration registers
The following System configuration registers, SYS_CF, exist:
• SYS_CFGDATA.
• SYS_CFGCTRL.
• SYS_CFGSTAT.
The registers are collectively referred to as SYS_CFG registers.
The registers enable communication between the MCC and Daughterboard Configuration
Controller to read and write a variety of system parameters, for example:
• Oscillators.
• Voltage.
• Current.
• Power.
To complete a CFG transfer in your application code, implement the following pseudo code:
• Clear the SYS_CFGSTAT Complete bit.
• For writes, set the SYS_CFGDATA value with your data value. For example, to set an
oscillator to 50MHz, write
50000000 to this register.
• Set the SYS_CFGCTRL register with the correct function and destination value. For
example, to read from the Motherboard oscillator 1, set the SYS_CFGCTRL register to
0x80100001 :
—Start =
1
— Write = 1
— DCC = 0
— Function = 1 (OSC)
—Site = 0 (MB)
— Position = 0
— Device = 1 , oscillator 1.
• Wait for the SYS_CFGSTAT Complete bit to be set to indicate that the read or write
transfer has completed.
• For reads, you must read the SYS_CFGDATA register to read the returned data.
Config SYS_CFGDATA
The SYS_CFGDATA Register characteristics are:
Purpose Holds the data value to be written or read during communication across
the SPI interface between the MCC and a Daughterboard Configuration
Controller.
Usage constraints There are no usage constraints.
Configurations Available in all configurations.
Attributes See Table 4-3 on page 4-8.
Table 4-17 shows the register bit assignments.
Table 4-17 SYS_CFGDATA Register bit assignments
Bits Name Description
[31:0] CFG data 32-bit configuration data register