User`s manual

PFLASH - Program FLASH Memory
3-184
3
Description
The PFLASH command loads an application or program into Flash
memory. The command line arguments are checked (e.g., does the
destination range lie completely within the Flash memory?, are
there overlapping address spaces?, are the address arguments
aligned?). If an argument does not pass, an appropriate error
message is displayed and control is passed back to the monitor with
the Flash memory contents undisturbed.
Physically, PPCBug is contained in two socketed 32-pin PLCC
Flash memory devices that together provide 1MB ($00100000) of
storage. PPCBug uses the entire memory contained in the two
devices. The executable code is checksummed at every power-on or
reset firmware entry. The result is checked with a pre-calculated
checksum contained in the last 16-bit word of the Flash image.
The element size is determined by the size (B, W, or L) option. The
default B.
If the programming agent is the debugger and it is resident in the
Flash memory, it may have to download the Flash memory driver.
The downloaded driver uses the board's system fail LED and
NVRAM to communicate programming errors. This hardware
notification of a Flash memory programming error is only
necessary if you are reprogramming the programming agent's text
and data space. Otherwise, errors are communicated by means of
the programming terminal (serial I/O).
Upon error free completion of the Flash memory programming,
control is passed back to the monitor. If the instruction execution
address argument is specified, control will be passed to this
address. If the programming agent is reprogrammed and the
instruction execution address argument is not specified, control
remains within the Flash memory driver (do nothing, wait for
reset).
If the Flash memory driver was downloaded, messages are not
displayed on the terminal. If return from the downloaded driver is
not possible, and the instruction execution or the local reset option