Rabbit 2000 - 7 BIOS Support for Program Cloning

45 pages

Save Page as PDF

To Next Page

To Next Page

To Previous Page

To Previous Page

Loading...

Designer’s

Handbook 27

7.

BIOS

Support

for

Program

Cloning

A

program

can

be

loaded

into

a

controller

by

compiling

it

using

Dynamic

C.

However,

this

is

awkward

and

slow

in

some

situations.

If

cloning

is

enabled

in

the

BIOS,

a

Rabbit-

based

system

can

copy

itself

into

another

controller

by

connecting

the

programming

ports

of

the

two

controllers

together

in

the

proper

way

as

shown

in

Figure

6.

Figure

6.

Programming

Cable

If

the

cloning

cable

is

connected

to

the

master,

the

master

detects

this

because

the

signal

CLKA

is

held

low.

This

is

detected

in

the

BIOS

after

the

reset

ends,

and

the

cloning

sup-

port

of

the

BIOS

is

then

invoked.

The

cloning

program

cold-boots

the

target

system

by

resetting

it

and

downloading

a

primary

boot

program.

The

master

then

sends

the

entire

BIOS

over

to

the

clone,

where

the

boot

program

receives

it

and

stores

it

in

RAM

(just

like

Dynamic

C

does

when

compiling

the

BIOS).

A

CRC

check

of

the

BIOS

is

performed

on

both

the

master

and

clone,

and

the

results

are

compared.

The

clone

is

reset

again,

and

the

BIOS

begins

running.

Finally,

the

master

sends

blocks

of

data

at

high

speed,

and

the

data

are

written

to

the

flash

memory.

Data

transfer

can

take

place

at

57,600

bps

or

115,200

bps.

When

the

entire

flash

contents

(except

for

the

system

ID

block)

have

been

transferred,

the

target

flashes

the

cable

LED

in

a

distinctive

pattern

to

indicate

that

the

programming

is

done.

At

that

point

the

cable

can

be

unplugged

and

plugged

into

another

target.

When

the

master

is

reset,

it

will

program

the

next

target.

To

enable

cloning,

two

options

must

be

set

at

the

top

of

the

BIOS.

First,

ENABLECLONING

should

be

set

to

1.

If

this

is

set,

the

BIOS

will

take

up

additional

mem-

ory

because

of

the

functions

required

for

cloning.

The

cloning

baud

rate

is

set

by

setting

CLONINGBAUDRATE

to

either

0

(57,600

bps)

or

1

(115,200

bps).

Once

cloning

is

enabled,

compile

your

program

to

flash,

then

detach

the

programming

cable

and

attach

the

cloning

cable.

Make

sure

the

“master”

end

of

the

cable

is

connected

to

the

master

controller

(the

cable

is

not

reversible)

and

that

pin

1

lines

up

correctly

on

J1

J2

RXA

GND

CLKA

+5 V

/RESET

TXA

N/C

STATUS

SMODE0

SMODE1

RXA

GND

CLKA

+5 V

/RESET

TXA

N/C

STATUS

SMODE0

SMODE1

RESET MASTER

CLONE STATUS

470 Ω

Master

Target

Being

Cloned

Table of Contents

Other manuals for Rabbit 2000

User Manual230 pages

Instruction & Reference Manual174 pages

Reference Manual120 pages

Getting Started Manual54 pages

Getting Started43 pages