NXP Semiconductors Kinetis KE1xZ256, Reference Manual

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48.5.7 Scan times
The TSI provides multi-scan function. The number of scans is indicated by
TSI_SINC[DECIMATION] that allow the scan number from 1 to 32. When
TSI_SINC[DECIMATION] is set to 0 (only once), the single scan is engaged. The 16-bit
counter accumulates all scan results until the scan times reaches
TSI_SINC[DECIMATION], and users can read TSI_DATA[TSICNT] to get this
accumulation. When DMA transfer is enabled, the counter values can also be read out by
DMA engine.
48.5.8 Clock setting
Both of self-cap front end and mutual-cap front end are driven by switching clock with
frequency Fsw. It comes from SSC clock with flatten emission energy. In addition, the
frequency of switching clock can be configured by TSI_SSC0, TSI_SSC1 and TSI_SSC2
(Refer to chapter Spread spectrum clocking for details). The clock source of SSC is from
Main Clock block in TSI. The frequency of main clock can be configured by
SETCLK<1:0>.
Figure 48-7. TSI clock
Example
• To use no SSC switching clock with frequency of 1MHz.
• Set SETCLK<1:0> to ‘01’ to get Fclkmain = 16.65MHz.
• Set SSC_MODE<1:0> to ‘10’ to disable SSC function.
• Set SSC_PRESCALE_NUM<7:0> to ‘0000-0111’ to get division 16 .
• Keep other registers in TSI_SSC0, TSI_SSC1 and TSI_SSC2 as default value.
• Then, Fsw = 16.65MHz/16 = 1.04MHz. Fsw is square wave pulse.
• To use PRBS mode SSC switching clock with central frequency of 1MHz.
Functional description
Kinetis KE1xZ256 Sub-Family Reference Manual, Rev. 3, 07/2018
1304 NXP Semiconductors