Atmel C51 3.3 Demo Mode

Operation Mode

C51 Microcontrollers Demo Board User Guide 3-14

4119C–8051–3/03

After the download of the HEX file, the program asks if you want to download another

HEX file in the second zone of the external Flash memory.

In this case you’ll have to switch MAP SELECT (to access second zone) and send

another HEX file in text mode.

All the external flash memory (128K bytes) is erased when ISP is used, even if you only

want to download one zone.

If you have one external Flash memory zone programmed, and later you want to add

another program to the second memory zone, you will have to downlo ad both programs

at the same time.

Note: The data transfer is seen on bar graph.

3.3 Demo Mode In demo mode, programs stored into external flash memory are executed to demon-

strate capability of Atmel Microcontrollers. To run external code we must have EA=0.

In this mode the first four bits of J11 (UC3:0) are used to select demo program and UC4

is used to select display (LCD or RS232).

Figure 3-7. Switch Utilities in Demo Mode

3.3.1 C51 Mode In C51 mode (Non Page Mode) switch J8 must be as shown in Figure 3-8.

J11

PSEN

ALE

ISP1

User Code

J11

J16

MAP SELECT

ISP2

Used to select demo program

Used to select display

Used to select memory zone