Cmsemicon CMS32L051 - Calculation of Transmit Clock Frequency

V1.2.2
CMS32L051 User Manual |Chapter 12 Universal Serial Communication Unit
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12.5.7 Calculation of transmit clock frequency
3-wire serial I/O (SSPI00, SSPI01, SSPI10, SSPI11, SSPI20, SSPI21) communication transmission clock
frequency can be calculated using the following calculation equations.
(1) Master device
(2) Slave device
Note The maximum enable transmit clock frequency is f
MCK
/6.
Note Because the value of SDRmn [15:9] is the value of bit15~9 of the serial data register mn (SDRmn) (0000000B~).
1111111B), so it is 0~127.
The operating clock(F
MCK
) depends on bit15 (CKSmn) of the serial clock selection register m (SPSm) and
the serial mode register mn (SMRmn).
(transmit clock frequency) = {the operating clock of the object channel (f
MCK
) frequency} (SDRmn[15:9]+ 1) 2[Hz]
(transmit clock frequency) = {Serial clock (SCLK) frequency provided by the master device}
Note
[Hz].