Synergy

Using SWO on Synergy Devices

In general, the J-Link DLL expects the trace clock to be equal to the CPU clock. As the Synergy device series allows to enable a pre-scaler for trace clock, this assumption is no longer valid resulting in incorrect SWO data are read. To make sure that the J-Link DLL behaves as expected, please make sure to not enter the actual CPU clock but the CPU clock multiplied with the ICKdivider configured in the System Clock Division Control Register (SCKDIVCR) divided by the trace clock divider configured in the Trace Clock Control Regigster (TRCKCR).

Example (S3A7)

• MOCO (8MHz)
• System Clock Division Control Register (SCKDIVCR[ICK[2:0]]): 0x4 --> * 1 / 16
• System Clock Source Control Register (SCKSCR[CKSEL[2:0]]): 0x1 --> MOCO selected as source for the ICLK (System Clock) and TRCLK (Trace Clock)
• Trace Clock Control Register (TRCKCR[TRCK[3:0]]): 0x1 --> /2

ICLK = 8MHz * 1 / 16 = 500 kHz CPU clock TRCLK = ICLK * 1 / 2 = 250 kHz Trace / SWO clock

CPU clock to be entered in the IDE project = ICLK * ICKdivider / TRCKdivider = 500 kHz * 16 / 2 = 4 MHz

Example (S7G2)

• MOCO (8MHz)
• System Clock Division Control Register (SCKDIVCR[ICK[2:0]]): 0x4 --> * 1 / 4
• System Clock Source Control Register (SCKSCR[CKSEL[2:0]]): 0x1 --> MOCO selected as source for the ICLK (System Clock) and TRCLK (Trace Clock)
• Trace Clock Control Register (TRCKCR[TRCK[3:0]]): 0x1 --> /2

ICLK = 8MHz * 1 / 4 = 2 MHz CPU clock TRCLK = ICLK * 1 / 2 = 1 MHz Trace / SWO clock

CPU clock to be entered in the IDE project = ICLK * ICKdivider / TRCKdivider = 2 MHz * 4 / 2 = 4 MHz