- Fri Jul 22, 2011 8:10 pm
#130586
I am attempting to program an LPC1114 via SWD and have found that there are inconsistencies between the ARM SWD interface specification and the implementation on the LPC1114.
1. In order to receive an ACK for CSYSPWRUPREQ, the flag CDBGRSTREQ must also be written to CTRL/STAT. This is not described in the ARM SWD v5 documentation.
2. The ARM specification shows clock cycles occurring during turnaround times in which the SWDIO pin changes from an input to an output. One document even describes a write command taking 46 clock cycles to complete counting the clocks during the turnaround. However, it is apparent from correctly writing the initialization sequence and reading the IDCODE register that the SWDCLK line should not be clocked during the turnaround time.
Can anyone confirm these discrepancies?
Is there any documentation about non-conformance to the ARM Debug v5 Interface on LPCs?
Thanks,
1. In order to receive an ACK for CSYSPWRUPREQ, the flag CDBGRSTREQ must also be written to CTRL/STAT. This is not described in the ARM SWD v5 documentation.
2. The ARM specification shows clock cycles occurring during turnaround times in which the SWDIO pin changes from an input to an output. One document even describes a write command taking 46 clock cycles to complete counting the clocks during the turnaround. However, it is apparent from correctly writing the initialization sequence and reading the IDCODE register that the SWDCLK line should not be clocked during the turnaround time.
Can anyone confirm these discrepancies?
Is there any documentation about non-conformance to the ARM Debug v5 Interface on LPCs?
Thanks,