Re: What's the problem with my JTAG?????
turned out that we were inadvertently causing the micro to enter an
undocumented test mode which disabled the JTAG due to a failed CAN
In our case on the LPC2294 it was caused by holding TD1 (pin22) low at
reset. Below is what we got from NXP for the LPC2294
As far as other "magic pins", here is a list for the LPC2294:
- pin 22: low at reset invokes a factory test mode <-- This is the one
the caused us problems due to a failed CAN Transceiver
- P0.14: low at reset invokes on-chip bootloader
- P1.20: low at reset enables ETM pins (P1.16 - P1.25)
- P1.26: low at reset enables JTAG pins (P1.26 - P1.31)
- P2.26 + P2.27: BOOT0 + BOOT1 pins state at reset control default
Sr. Electronic Design Engineer
2604 Highway 20 North
Jamestown, ND 58401
From: l... [mailto:l...] On Behalf
Sent: Thursday, December 13, 2007 4:08 AM
Subject: [lpc2000] Re: What's the problem with my JTAG?????
Perhaps you can program it with some other port. Serial, USb or
ethernet perhaps??? For serial use Flash Magic.