SWD issue in Cortex-m0

We are using Cortex-M0 DesignStart Pro to design MCU. When we use SWD to download grogram to flash in FPGA(Cortex_m0 mcu inside),  we cannot to connect keil with FPGA, and Keil shows:" Could not stop Cortex-M device!Please check the JTAG cable. "

Attached are keil display error messages, simulation waveforms, and data analysis captured by the logic analyzer.

SWD_signals.docx