P4080 Development System User’s Guide, Rev. 0
Freescale Semiconductor
33
Architecture
5.2.6
CONFIG
CONFIG monitors and/or sets selected configuration signals.
In some instances, CONFIG maps switch settings into direct configuration outputs, while in others (such
as SYSCLK), it maps a 3-position switch into a 16-bit register initialization pattern, which is subsequently
used to initialize the clock generator.
5.2.7
VELA
VELA is a simple microsequencer used to monitor sequence in requested changes in board configuration
upon a signal (generally a register write from PCI). When detected, bits in a PX_EN[1:8] register allow a
corresponding PX_SW[1:8] register to be driven onto configuration pins during a system restart.
5.2.8
OCM
The off-line configuration manager (OCM), is a small microprocessor (GMSA) that contains an embedded
CPU core, 8-Kbyte SRAM and I/O peripherals (UART, I
2
C, GPIO and timers). The standard OCM
software performs the following functions:
•
Monitors PX_VCTL[GO] to avoid interfering with self-shmoo
•
Loads ngPIXIS SW/EN registers from external I
2
C EEPROM
•
Modifies ngPIXIS misc registers from external I
2
C EEPROM
•
Modifies VCORE output voltage based on SW_VCORE(0:1) settings
•
User interaction to allow programming I
2
C EEPROM (even with power off)
•
Background data collection on VCORE, ICORE, TEMP, and so on
•
Other system control functions (reset, power cycle, and so on)
This figure shows the block diagram of the OCM component.
Figure 22. OCM GMSA Implementation
boot
lo
ader
Private
GMSA
I
2
C
Controller
IPL
EEPROM
IOPort
Regs
Shared
256-byte
SRAM
8-Kbyte SRAM
Host
Processor