Flash Magic Forum

In-System Programming Support => P89C51Rx+/P89C51Rx2/P89C66x/P89C6xX2/P89V66x => Topic started by: a9o1o8o on January 13, 2016, 10:23:36 pm

Title: P89C662HBA trouble
Post by: a9o1o8o on January 13, 2016, 10:23:36 pm
 OK,if I  set  security bit1 or set security bit2 or set security bit3(May be set all three security bit )when download my code to P89C662HBA,Does it will cause I can't  Handshake to MCU successuflly next time?Who can help me?
Title: Re: P89C662HBA trouble
Post by: a9o1o8o on January 13, 2016, 10:32:06 pm
I mean that just cant't read chip‘s Identity number or BOOT VECTOR or STATUS BYTE's value? if I set security bit
Title: Re: P89C662HBA trouble
Post by: Andy Ayre on January 13, 2016, 11:49:31 pm
The functionality of each bit is described in the P89C662 data sheet from NXP. Only set the security bits if you are sure what they do.

Andy
Title: Re: P89C662HBA trouble
Post by: a9o1o8o on January 14, 2016, 05:36:24 pm
You mean that I cant't read chip‘s Identity number or BOOT VECTOR or STATUS BYTE's value?
Title: Re: P89C662HBA trouble
Post by: Andy Ayre on January 15, 2016, 12:05:54 am
Look at table 16 in the data sheet. It tells you exactly what each bit does. It looks to me like yes, you should still be able to use ISP and still be able to read the signature, boot vector and status byte.

A full chip erase will erase all the security bits.

Andy
Title: Re: P89C662HBA trouble
Post by: a9o1o8o on January 17, 2016, 06:10:06 pm
Can I erase the full chip through ISP this way?
Title: Re: P89C662HBA trouble
Post by: Andy Ayre on January 18, 2016, 01:08:48 am
According to the data sheet, yes.