ISP Entry using DTR and RTS

[Nor_Ain]

Hello all,

I'm try to implement the DTR and RTS signal to enter the ISP mode and RESET.
However, I'm facing a problem with the DTR and RTS signal. Do i need to connect the DTR and RTS from RS232 directly into 74LS125 chip? Or I need a
RS232 tranceiver chip to connect these  DTR and RTS?

Any help highly appreciated.

Thanks.

[Andy Ayre]

RS232 does not use TTL logic levels. You can either use an RS232 transceiver or you can use transistors. Please see the schematics of the Keil evaluation boards on keil.com for ideas.

Andy

[govind]

please send me ciruit diagram of flash magic programmer.

[Andy Ayre]

We recommend you start off with an evaluation board from a well known manufacturer. They always include circuit diagrams.

Andy