Can't start ISP masked-ROM boot loader code ,P89C662HBA

[a9o1o8o]

Good chip Serial debugging assistant software Screen

[a9o1o8o]

May be bad chip waveforms

[a9o1o8o]

May be bad chip Serial debugging assistant software Screen On,the last picture upload failed. The picture is stable data which is not "U"

[Andy Ayre]

because flash magic software so quickly that I can't capture waveforms in time ,so I use Serial debugging assistant software Send "U" persistent. The good chip will Reply "U". Good chip waveforms

You need a scope that can trigger on an edge then show you what it captured. Essential for working with embedded systems.

[Andy Ayre]

Try using a terminal program such as PuTTY. Send a 'U' to the device and see if you get a 'U' back. Use 9600 baud then 19200 baud, 8N1. If you get that working then compare the waveforms at RxD and TxD with the ones generated by Flash Magic.