ICS TRIPLEX T8403处理器卡件，T8403使用速度
与基于M68000的固件的比较如果您使用了摩托罗拉的一个或多个其他调试包，你会发现RISC 187Bug非常相似，在制作后适当考虑到M68000和M88000 CPU架构。这些差异是
主要体现如下：
❏ 的指令助记符和寻址模式汇编程序/反汇编程序在某些方面有所不同。
❏ 187Bug使用寄存器而不是堆栈来传递陷阱#496处理程序的参数。
❏ 187Bug中的交互命令更加一致。对于例如，命令和参数之间的分隔符可能现在可以互换逗号或空格。
ICS TRIPLEX T8403处理器卡件187Bug实现MVME187Bug主要是在“C”编程中编写的语言，提供了可移植性和可维护性的好处。必要时，汇编程序已以单独的形式使用只包含汇编代码的编译模块；无混合使用语言模块。实际上，187Bug包含在四个44针中的两个中PLCC/CLCC EPROM，提供512KB（128K字）的存储。无论空间有多大，两个EPROM都是必要的由于32位面向字的M88000内存总线架构，实际上被固件占用。
可执行代码在每次通电或重置时进行校验和固件条目和结果（包括预先计算的测试EPROM中包含的校验和是否为预期零。因此，提醒用户不要修改EPROM除非采取重新校验和预防措施。内存要求187Bug的程序部分大约有512KB的代码，包括下载、调试器和诊断包以及完全包含在EPROM中。上的EPROM插槽MVME187从位置$FF800000开始映射。
187Bug需要至少64KB的连续读/写要操作的内存。ENV命令控制该内存块的位置。
无论板载RAM位于何处，前64KB都是用于187Bug堆栈和静态变量空间，其余为保留为用户空间。
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.
