User`s manual

Rabbit 4000 Designer’s Handbook rabbit.com 39

6.2 BIOS Flowchart

The following flowchart summarizes the functionality of the BIOS:

Figure 6-1 BIOS Flowchart

NOTE: To use the diagnostic port on the RCM43xx, you must first reset the board

and then plug in the “Diag” header of the programming cable.

NOTE: If the programming cable is connected at power-up, the Rabbit will never

execute the BIOS, since the cable holds the board in coldboot mode.

Set up memory

control and basic

BIOS services.

Is the programming

cable connected?

Divert to BIOS

service?

Call user application

program (main).

Start Dynamic C

communications

and state machine.

Start at

address 0

Yes

Act as master

for cloning.

BIOS services for

user application

program.

Application

Program