ICS TRIPLEX T8403處理器卡件，T8403使用速度
與基于M68000的固件的比較如果您使用了摩托羅拉的一個或多個其他調(diào)試包，你會發(fā)現(xiàn)RISC 187Bug非常相似，在制作后適當考慮到M68000和M88000 CPU架構。這些差異是
主要體現(xiàn)如下：
? 的指令助記符和尋址模式匯編程序/反匯編程序在某些方面有所不同。
? 187Bug使用寄存器而不是堆棧來傳遞陷阱#496處理程序的參數(shù)。
? 187Bug中的交互命令更加一致。對于例如，命令和參數(shù)之間的分隔符可能現(xiàn)在可以互換逗號或空格。
ICS TRIPLEX T8403處理器卡件187Bug實現(xiàn)MVME187Bug主要是在“C”編程中編寫的語言，提供了可移植性和可維護性的好處。必要時，匯編程序已以單獨的形式使用只包含匯編代碼的編譯模塊；無混合使用語言模塊。實際上，187Bug包含在四個44針中的兩個中PLCC/CLCC EPROM，提供512KB（128K字）的存儲。無論空間有多大，兩個EPROM都是必要的由于32位面向字的M88000內(nèi)存總線架構，實際上被固件占用。
可執(zhí)行代碼在每次通電或重置時進行校驗和固件條目和結果（包括預先計算的測試EPROM中包含的校驗和是否為預期零。因此，提醒用戶不要修改EPROM除非采取重新校驗和預防措施。內(nèi)存要求187Bug的程序部分大約有512KB的代碼，包括下載、調(diào)試器和診斷包以及完全包含在EPROM中。上的EPROM插槽MVME187從位置$FF800000開始映射。
187Bug需要至少64KB的連續(xù)讀/寫要操作的內(nèi)存。ENV命令控制該內(nèi)存塊的位置。
無論板載RAM位于何處，前64KB都是用于187Bug堆棧和靜態(tài)變量空間，其余為保留為用戶空間。
Comparison with M68000-Based Firmware
If you have used one or more of Motorola's other debugging
packages, you will find the RISC 187Bug very similar, after making
due allowances for the architectural differences between the
M68000 and M88000 CPU architectures. These differences are
primarily reflected as follows:
? Instruction mnemonics and addressing modes of the
assembler/disassembler differ somewhat in 187Bug.
? 187Bug uses registers instead of the stack for the passing of
arguments to or from the TRAP #496 handler.
? The interactive commands in 187Bug are more consistent. For
example, delimiters between commands and arguments may
now be commas or spaces interchangeably.
187Bug Implementation
MVME187Bug is written largely in the “C” programming
language, providing benefits of portability and maintainability.
Where necessary, assembler has been used in the form of separately
compiled modules containing only assembler code; no mixed
language modules are used.
Physically, 187Bug is contained in two of the four 44-pin
PLCC/CLCC EPROMs, providing 512KB (128K words) of storage.
Both EPROMs are necessary regardless of how much space is
actually occupied by the firmware, because of the 32-bit wordoriented M88000 memory bus architecture.
The executable code is checksummed at every power-on or reset
firmware entry, and the result (which includes a pre-calculated
checksum contained in the EPROMs), is tested for an expected zero.
Thus, users are cautioned against modification of the EPROMs
unless re-checksum precautions are taken. Memory Requirements
The program portion of 187Bug is approximately 512KB of code,
consisting of download, debugger, and diagnostic packages and
contained entirely in EPROM. The EPROM sockets on the
MVME187 are mapped starting at location $FF800000.
187Bug 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 187Bug stack and static variable space and the rest is
reserved as user space.
