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DEVELOPMENT Utilities for a MICROPROCESSOR to Be Executed FROM a Technician Terminal

IP.com Disclosure Number: IPCOM000039403D
Original Publication Date: 1987-Jun-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 2 page(s) / 14K

Publishing Venue

IBM

Related People

Britt, BJ: AUTHOR [+3]

Abstract

This article describes a technique which allows board level hardware checks in a microprocessor without the need for an external piece of testing hardware. The microcode that supports development utilities is included in the erasable programmable read-only memory (EPROM) that is resident on a card installed in the technician terminal. A command can be entered from the keyboard to either modify data or retrieve data within the microcode and/or the microprocessor. The utilities described below have been built into the predefined set of hardware and microcode instructions to allow the programmer to verify internal data on the assembly line diagnostic link (ALDL) or the probe card without having a development system attached.

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DEVELOPMENT Utilities for a MICROPROCESSOR to Be Executed FROM a Technician Terminal

This article describes a technique which allows board level hardware checks in a microprocessor without the need for an external piece of testing hardware. The microcode that supports development utilities is included in the erasable programmable read-only memory (EPROM) that is resident on a card installed in the technician terminal. A command can be entered from the keyboard to either modify data or retrieve data within the microcode and/or the microprocessor. The utilities described below have been built into the predefined set of hardware and microcode instructions to allow the programmer to verify internal data on the assembly line diagnostic link (ALDL) or the probe card without having a development system attached. By entering commands via FASTDRV or FASTCHK, data in the microprocessor internal random-access memory (RAM) or its attached storage can be displayed or modified. In the commands, the X in the XF is either a 5 for the probe or a 9 for the ALDL card. DISPLAY FUNCTION FROM THE PERSONAL COMPUTER (PC) KEYBOARD XF 00 will display the contents of the internal RAM on the microprocessor. 9F 00 will display the internal RAM of the ALDL which will show the register banks, data bytes and flags. XF 01 PG will display any page of code/data within the microprocessor's storage. PG is the first two hex digits of the page to be selected for viewing on the monitor. 5F 01 08 will display 256 bytes of probe microcode starting at address 0800 hex. The values of memory mapped input/output devices can be determined. PATCH THE MICROPROCESSOR INTERNAL RAM FROM THE PC KEYBOARD XF 02 DB XX will modify or patch any byte in the microprocessor's internal RAM. DB is the data byte that is to be modified and XX is the new value to be placed in that location. 9F 02 27 02 will modify data byte 27 hex with a two. With DB = FF, any 256 bytes of RAM can be set to zero. The command would be XF 02 FF PG, and PG is the high byte of the RAM address,
i.e., 43 for 4300. PATCH EXTERNAL RAM ATTAC...