IAP turn to ISP without reset MCU

[Canh]

Author :NT Canh
Datte :31/7/2004

Dear sir.

I want to turn  MCU 89c51rd2 from  IAP mode to ISP mode to dowload hexfile into FLash memory and turn it from ISP mode to IAP mode without reset hardware.But I haven't performed yet.So,please help me.How can i do that .Because I want to remote control MCU  via PC like PLC.

Thanhks

[Andy Ayre]

In your application wait for a command to be received via the UART. Upon reception of this command, echo the command back out the UART along with a ".".
Next use IAP to set the status byte and then start the watchdog timer and let it time out.

This will put you into ISP mode.

Use Flash Magic for whatever operations you need then use the Execute option in Flash Magic to execute your new application. The Execute feature only works on rev G or later if you are using the 89C51RD2Hxx, and I am fairly sure (but not 100%) that it works on the 89C51RD2xx.

To send the command from Flash Magic to put the device into ISP mode, choose Start BootROM from the ISP menu.

[canh]

Author :Canh
date: 6-8-2004
Dear Sir:

In my application,when I received a command Start BootRoom "boot" from Flashmagic via UART .Upon the reception of this command ,i have echoed the command back out the UART a long with "." Next  use IAP to set the status byte follow:

MOV R0,#12
MOV R1,#06H or  86H (watchdog timer)
MOV DPH,#00H
MOV DPL,#01
MOC ACC,#01H
LCALL 0FFF0H  
and i started watchdog timer:

MOV 0A6H,#1EH
MOV 0A6H,#0E1H

However,MCU doesn't put into ISP mode.
Please help me.

[erikm]

Next use IAP to set the status byte and then start the watchdog timer and let it time out.

This will put you into ISP mode.

Have a look at NoTouch, it does exactly what you want.

Erik