Hi,
I want to program 89C61X2. When I try to read security bits, Flash Magic has a message "Unable to connect at a specified baud rate. Try reducing the baud rate. Reset the hardware into ISP mode again." I already use the lowest baud rate. Why the MCU cannot be connected?
You can go to page 13
http://www.keil.com/dd/docs/datashts/philips/p89c6xx2_ds.pdf
and page 17
http://pdfserv.maxim-ic.com/en/ds/MAX220-MAX249.pdf
to see my schematic.
Also, I connected pin2 of DB9-F to pin14 of MAX232,
pin3 of DB9-F to pin13 of MAX232,
pin5 of DB9-F to GND.
I want to program 89C61X2. When I try to read security bits, Flash Magic has a message "Unable to connect at a specified baud rate. Try reducing the baud rate. Reset the hardware into ISP mode again." I already use the lowest baud rate. Why the MCU cannot be connected?
You can go to page 13
http://www.keil.com/dd/docs/datashts/philips/p89c6xx2_ds.pdf
and page 17
http://pdfserv.maxim-ic.com/en/ds/MAX220-MAX249.pdf
to see my schematic.
Also, I connected pin2 of DB9-F to pin14 of MAX232,
pin3 of DB9-F to pin13 of MAX232,
pin5 of DB9-F to GND.