FLASHMON: ATMEL DEVICES WITH EXTERNAL UART DO NOT WORK

Information in this article applies to:

• C51 Version 7

QUESTION

I want to use FlashMon on my T89C51CC01 or T89C51RD2 with an external UART. To do this, I set SERIAL to 2 in the CONFIG.INC.

; SERIAL: Defines the UART and the baudrategenerator
SERIAL        EQU  2         ; 0 = on-chip UART with timer1...
                             ; 1 = on-chip UART with timer2...
                             ; 2 = use external 16550/16450 UART...

When my application downloads communication breaks down and the error

CONNECTION TO TARGET SYSTEM LOST

is reported. What's wrong?

ANSWER

It is not possible to use an external UART with FlashMon and Atmel devices.

During flash programming, MOVX instructions may only address one flash page before it is programmed. However, MOVX instructions are required to get the data from the external UART (since it is mapped into XDATA space).

MORE INFORMATION

• Refer to Application Note 174 for more information on how to use FlashMon on the Atmel AT89C51SND1

SEE ALSO

• FLASHMON: FLASHMON CRASHES WHILE LOADING ON ATMEL DEVICE
• µVision DEBUGGER: SERIAL INTERRUPT OF MONITOR DOES NOT WORK

Last Reviewed: Monday, February 14, 2005