Atmel AT91EB42 Programmed Default Memory Mapping, Downloader, Default Speed, On-board Software

The On-board Software

3.3Programmed Default Memory Mapping

Table 3-1defines the mapping defined by the boot program.

Table 3-1. Memory Map

Part Name	Start Address	End Address	Size	Device
U1	0x01000000	0x011FFFFF	2M Bytes	Flash
				AT49BV1604
U2-U3	0x02000000	0x02040000	256K Bytes	SRAM

		The boot software program, FTS and SRAM downloader are in sectors 1 and 2 of the
		Flash device. Sectors 2 to 8 support the Angel Debug Monitor.
		Sector 24 at address 0x0110 0000 must be programmed with a boot sequence to be
		debugged. This sector can be mapped at address 0x0100 0000 (or 0x0 after a reset)
		when the jumper JP1 is in the USER position.
3.4	SRAM	The SRAM downloader allows an application to be loaded in the SRAM at the address
	Downloader	0x02000000, then activated. It is started by the boot if the SW2 button is pressed at
		reset.

The procedure is as follows:

1.Connect the AT91EB42 Evaluation Board to the host PC serial “A” connection using the straight serial cable provided.

2.Power-on or press “RESET”, holding down the SW2 button at the same time. Wait for D2 to light up and then release SW2.

3.Start the BINCOM utility, available in the AT91 library, on the host computer:

Select the port for communications (COM1 or COM2, depending on where you con- nected the serial cable on the host PC) and the baud rate for communications (115200 bds, 1 stop bit, no parity).

Open the file to be downloaded and send it. Wait for the end of the transfer.

4.Press any button to end the download. The control is switched to the address 0x02000000.

3.5Angel Monitor The Angel monitor is located in the Flash from 0x01002000 up to 0x0100FFFF. The boot program starts it if no button is pressed at reset.

When Angel starts, it recopies itself in SRAM in order to run faster. The SRAM used by

Angel is from 0x02020000 to 0x02040000, i.e., the highest half part of the SRAM.

The Angel on the AT91EB42 Evaluation Board can be upgraded regardless of the ver- sion programmed on it.

Note that if the debugger is started through ICE while the Angel monitor is on, the

Advanced Interrupt Controller (AIC) and the USART channel are enabled.

3.6Programmed As the speed of the AT91M42800 is programmable, the boot software program initial-

Default Speed	izes the device to run as fast as possible, i.e., at 40 MHz. The boot software program
	and the functional test software are run at this speed. The SRAM downloader, after ini-
	tialization of the USARTs, enters the processor in idle mode and activates the
	downloaded application at this speed. When Angel is started, it also runs at 40 MHz and
	the user should not modify this frequency without reprogramming the speed of the
	USARTs.

3-2

AT91EB42 Evaluation Board User Guide