I have bought two chip P89v51rb2 and p89c669.
P89v51 can be download programs by flashmagic software,but the P89c669 can't.
when the chips are power on when haven't been programmed, I found the RxD and Txd is 5v on p89v51. The RXD0 is 5v on p89c669,but the TxD0 is 0v, while RXD1 and TXD1 is 5v. the ALE is 1.7V and can measured pulse signal,so the crystal is work.
what should I do?
These devices have different methods of being placed into ISP mode. Please refer to the user manual for the 89C669 and make sure you are meeting the requirements during reset of the device.
Andy
what's the different?
Please refer to the user manuals/datasheets for the two devices. The ISP entry methods are described in full in there.
Andy
I have download the user manual and datasheet of p89c669, but have't found any special specification about ISP
How about most of chapter 7? In particular section 7.3 "Hardware Activation of the Boot Loader"
Andy
The boot loader can also be executed by holding PSEN LOW, EA greater than VIH (such as +5 V), and ALE HIGH (or not connected)
at the falling edge of RESET.
yes, but p89c669 can not work,p89v51 work
Try the debugging steps here:
http://www.flashmagictool.com/debugstart.html
They guide you through using Hyperterminal (or similar) to send a 'U' to the device. If you don't get a 'U' back then chances are you are not placing the device into ISP mode. Check the voltages at the Reset, ES, PSEN, etc. pins and that there is a sine wave on XTAL1 and XTAL2...
Andy