LPC1517 - ISP via USART not working / suspicious behaviour

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by hlsa on Wed Aug 27 08:26:07 MST 2014
I would like to use the ISP via USART programming functionality of the LPC1517FBD48 device.

Therefore I set ISP0 & ISP1 low. Uart_RX is connected to PIO0_14 (Pin 22). Uart_TX is connected to PIO0_15 (Pin23).
I am using the internal Oscillator.
On the software side I am using FlashMagic PS .Net Rev. 8.18.

Unfortunately communication with the ISP Bootloader does not work.

I made several measurements & tests to avoid that it is just a stupid mistake:
  [*]I measured ISP0 & ISP1 directly at the device. Both are low at PowerOn. Additionally I am sure that the Software, which I downloaded before via JTag, does not start.
  [*]CRP is disabled.
  [*]I tried the following baudrates: 2400, 4800, 9600, 38400, 57600, 115200. Before changing baudrate, I repowered the device to restart ISP autobaud detection.
  [*]Data from the PC is received on the RX line with the baudrate that I have set before on the PC side. Sending a character manually results in the transfer of the correct character (verified via Oscilloscope).
  [*]The device works properly via JTAG.
  [*]Neither the ISP Pins nor the USART Pins are used by my application. They are only used for ISP.

Something which is really strange: I can measure that the device sends something on the TX line to the PC. However, the baudrate is about 1000.

The only idea left is chip errata! Anyone having ISP via USART running on this device?

Best regards,