MAX187 Evaluation System/Evaluation Kit

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3

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EPROM Resident Program

A small bootstrap program is stored in the EPROM

located on the 68HC16 board. The EPROM resident

program initializes the 68HC16, tests the static RAM,

configures the chip-select logic, establishes serial com-

munications with the host, and downloads a program

into RAM. It starts operating on power-up or whenever

the RESET button is pressed. After RESET, it tests the

RAM and then waits to receive a character on its serial

port before transmitting its identification banner.

RAM Resident Program

KIT187.S19 and MIN187.S19 are 68HC16 RAM-resident

programs that are transferred from disk to the static RAM

on the 68HC16 module. They are used transparently by

the example programs. The example programs that do

not require the full command set of KIT187 download the

MIN187 program, which is smaller and implements only

the read and collect commands. Because the MIN187

occupies less user RAM, more sample data can be col-

lected (MIN187 can collect approximately 400 more

samples than KIT187 before it must upload the samples

to the host.) When the KIT187 program is running, it

offers the commands listed in Table 1. The MIN187 pro-

gram commands are listed in Table 2.

Personal Computer Program

MAX187.EXE, which runs on an IBM-compatible comput-

er, is a terminal program that establishes communication

with the 68HC16 module and allows the user to down-

load and run a Maxim-provided RAM resident program.

The serial communication baud rate is initiated at 1200

baud to ensure proper operation with slower systems.

The MAX187.EXE program provides several commands

that are associated with the host computer. These func-

tions are listed in Table 3.

The MAX187.EXE program can store the text of a termi-

nal session in a log file. To begin recording the terminal

session, press ALT+O [the letter O]. The program will

ask for a file name. Press ENTER to accept the default

file name, or type in a different name. If there is already

a file with that name, the old file will be erased. To close

the file, press ALT+C. The log file will contain the com-

plete text of the terminal session from the time when the

file is opened until the file is closed.

Graphing Program

The program SAMPL187.BAS samples the MAX187

and draws a graph of voltage over time. Preset sample

rates range from 2.5ksps to 10ksps. The time base is

approximate and there is no triggering mechanism, so

this program is only suitable for observing the wave-

forms of an external frequency generator.

Table 1. Commands Available when

KIT187.S19 is Running

Table 2. Commands Available after

MIN187 has been Downloaded

KEY

FUNCTION

Space

V

Repeatedly read the MAX187 and print result in

decimal.

R

O

Oscilloscope test; observe system timing by operat-

ing the MAX187 at high speed without processing

the data.

S

L

D

T

Read the MAX187 and print result in decimal.

Read the MAX187 and print result in hexadecimal.

Set the state of the SHDN pin.

Display low-power menu.

Set power-up delay and sleep time

(low-power menu only).

Test the accuracy using the current power-up delay

and sleep time settings (low-power menu only).

M

Return to main menu (low-power menu only).

?

List the available commands.

KEY

FUNCTION

?

r

Read the MAX187 and display the value as a 2-byte

hexadecimal number.

c

ESC

Exit the evaluation software.

Print RAM resident program version and list of com-

mands available.

Collect and upload a number of data samples to the

host PC. Samples can be collected at full speed, or

collected with a fixed delay, or collected in accor-

dance with an external clock. Approximately 16,000

samples may be collected and they can be dis-

played in either decimal or in hexadecimal.