HP P Class 450/500/550/600/650/700/750 Reference Manual page 56

System Board
Devices on the SMBus
LEDs), hardware monitoring (temperature and voltage), early diagnostics (CPU, DIMMs,
PLLs, boot start), run-time diagnostics (CPU errors, package intrusions), and other
miscellaneous functions (such as special OK/FAIL symbols based on a smiling face).
The integrated microprocessor includes a Synopsys cell based on Dallas "8052" equivalent,
a 2 KB boot ROM, 256 bytes of data RAM, an I2C cell, an Analog-to-Digital (ADC) with 5
entries, and an additional glue logic for interrupt control, fan regulation, and a status
panel control.
MaxiLife downloads its code in 96 milliseconds from an I2C serial EEPROM. The total
firmware (MaxiLife 8051-code, running in RAM) size is 5 KB. As it exceeds the 2 KB
program RAM space, a paging mechanism will swap code as it is required, based on a 512
byte buffer. The first 2 KB pages of firmware code is critical because it controls the initial
power
on/reset to boot the system. This initial page is checked with a null-checksum test and the
presence of MaxiLife markers (located just below the 2 KB limit).
If the boot block has been corrupted, the Firmware can start from its 'crisis' block. To do
this, set the System board switch 10 to the Closed position.
MaxiLife is partially replacing HP ASIC (Little Ben), and provides the necessary hardware
monitoring control. However, MaxiLife is not accessible in I/O space or memory space of
the system platform, but only through the SMBUS (which is a sub-set of the I2C bus), via
the PCI/ISA chipset (PIIX4E South Bridge). Its I2C cell may operate either in Slave or
Master mode, switched by firmware, or automatically in case of 'Arbitration' loss.
As a monitoring chip, MaxiLife reports critical errors at start-up, and as such is powered
by Vstandby (3.3V) power. For MaxiLife to work correctly, the PC Workstation must always
be connected to a grounded outlet. This enables the Personal Workstation's hardware
monitoring chip to be active, even if the system has been powered off.
Test Sequence and Error Messages
Refer to the section "MaxiLife Test Sequence and Error Messages" in the chapter "Tests
and Error Messages" for detailed information about the different test sequences and error
messages.
56 Chapter 2