FBM230 P0926GU擴展模塊，FOXBORO使用進(jìn)展
內存要求172Bug的程序部分大約有512KB的代碼，由下載、調試器和診斷包組成，包含完全在閃存或PROM中。172Bug從地址$FF800000執行，無(wú)論是在閃存還是EPROM。如果拆下J21針腳9和10處的跳線(xiàn)，則地址空間的閃存和EPROM交換。適用于MVME172-2xx系列板（MVME172LX），工廠(chǎng)發(fā)貨配置帶有跳線(xiàn)J21針腳9-10已刪除（172Bug在EPROM中運行）。
FBM230 P0926GU擴展模塊172Bug初始堆棧完全改變了8KB的SRAM內存，atDRAM可以是ECC或奇偶校驗類(lèi)型。DRAM夾層映射在連續從零開(kāi)始（00000000美元），第一大。有兩個(gè)相同大小但不同類(lèi)型的夾層，映射奇偶校驗DRAM到選定的基址，ECC夾層將跟隨。如果兩者都有夾層為ECC型，底層為第一層。172Bug需要2KB的NVRAM來(lái)存儲電路板配置，通信和引導參數。該存儲區始于$FFFC16F8，結束于$FFFC1EF7。172Bug需要至少64KB的連續讀/寫(xiě)內存運轉ENV命令控制內存塊的位置位于。無(wú)論板載RAM位于何處，前64KB用于172Bug堆棧和靜態(tài)變量空間，其余保留作為用戶(hù)空間。無(wú)論何時(shí)重置MVME172LX，目標PC都會(huì )初始化為對應于用戶(hù)空間開(kāi)頭的地址，目標堆棧指針初始化為用戶(hù)內的地址空間，目標中斷堆棧指針（ISP）設置為用戶(hù)的頂部空間在通電或重置時(shí)，SRAM基址的地址偏移量$C000是命令驅動(dòng)的；它執行各種操作以響應在鍵盤(pán)上輸入的命令。當172 Bug>提示時(shí)出現在終端屏幕上，調試器已準備好接受調試器命令。當屏幕上出現172 Diag>提示時(shí)，將顯示調試器已準備好接受診斷命令。要從一種模式切換到另一種模式，請輸入SD（切換目錄）。到檢查當前所在目錄中的命令，使用幫助命令（HE）。您輸入的內容存儲在內部緩沖區中。只有在輸入回車(chē)。這允許您更正輸入錯誤，如果必要時(shí)，使用調試包中描述的控制字符摩托羅拉68K CISC CPU用戶(hù)手冊，第1章。
Memory Requirements
The program portion of 172Bug is approximately 512KB of code,
consisting of download, debugger, and diagnostic packages and contained
entirely in Flash memory or PROM.
The 172Bug executes from address $FF800000 whether in Flash or
EPROM. If you remove the jumper at J21 pins 9 and 10, the address spaces
of the Flash and EPROM are swapped. For MVME172-2xx series boards
(MVME172LX), the factory ship configuration is with jumper J21 pins 9-
10 removed (172Bug operating out of EPROM).
The 172Bug initial stack completely changes 8KB of SRAM memory atDRAM can be ECC or parity type. DRAM mezzanines are mapped in
contiguously starting at zero ($00000000), largest first. With two
mezzanines of the same size but different types, parity DRAM is mapped
to the selected base address and the ECC mezzanine will follow. If both
mezzanines are ECC type, the bottom one is first.
The 172Bug requires 2KB of NVRAM for storage of board configuration,
communication, and booting parameters. This storage area begins at
$FFFC16F8 and ends at $FFFC1EF7.
172Bug 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 172Bug stack and static variable space and the rest is reserved
as user space. Whenever the MVME172LX 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.
address offset $C000 from the SRAM base address, at power-up or reset172Bug is command-driven; it performs its various operations in response
to commands that you enter at the keyboard. When the 172-Bug> prompt
appears on the terminal screen, the debugger is ready to accept debugger
commands. When the 172-Diag> prompt appears on the screen, the
debugger is ready to accept diagnostics commands.
To switch from one mode to the other, enter SD (Switch Directories). To
examine the commands in the directory that you are currently in, use the
Help command (HE).
What you key in is stored in an internal buffer. Execution begins only after
the carriage return is entered. This allows you to correct entry errors, if
necessary, with the control characters described in the Debugging Package
for Motorola 68K CISC CPUs User’s Manual, Chapter 1.
