Memory Requirements; Table 3-1. Memory Offsets With 162Bug - Motorola MVME162P-344 Series Installation And Use Manual

162Bug Firmware

Memory Requirements

3
.
4/8/16/32MB synchronous DRAM (SDRAM). Appears
as parity memory at 1/8/16MB, ECC at 32MB.
3-4
The program portion of 162Bug is approximately 512KB of code,
consisting of download, debugger, and diagnostic packages contained
entirely in Flash memory or in EPROM.
The 162Bug firmware executes from address $FF800000 whether in Flash
or EPROM. If you set switch S4 segment 5 to
Flash and EPROM are swapped. For MVME162P-244 and -344 series
boards (MVME162P4), the factory ship configuration except in the no-
VMEbus case has switch S4 segment 5 set to
of Flash).
The 162Bug initial stack completely changes 8KB of SRAM memory at
addresses $FFE0C000 through $FFE0DFFF, at power-up or reset.

Table 3-1. Memory Offsets with 162Bug

Type of Memory Present
The synchronous DRAM can be modeled as ECC or parity type, as
indicated above.
The 162Bug firmware requires 2KB of NVRAM for storage of board
configuration, communication, and booting parameters. This storage area
begins at $FFFC16F8 and ends at $FFFC1EF7.
162Bug requires a minimum of 64KB of contiguous read/write memory to
operate. The ENV command controls where this block of memory is
located. Regardless of where the onboard RAM is located, the first 64KB
is used for 162Bug stack and static variable space and the rest is reserved
as user space. Whenever the MVME162P4 is reset, the target PC is
initialized to the address corresponding to the beginning of the user space,
and the target stack pointers are initialized to addresses within the user
space, with the target Interrupt Stack Pointer (ISP) set to the top of the user
space.
, the address spaces of the
ON
(162Bug operating out
OFF
Default DRAM
Base Address
$00000000
Computer Group Literature Center Web Site
Default SRAM
Base Address
$FFE00000
(onboard SRAM)