Cmsemicon CMS32L051 - Input Switching Control Register (ISC)

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CMS32L051 User Manual |Chapter 12 Universal Serial Communication Unit
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12.3.14 Input switching control register (ISC)
When implementing LIN-bus communication via UART0, the ISC1 and ISC0 bits of the ISC register are
used for the coordination of external interrupts and timer array units. If bit0 is set to 1, the input signal from
the serial data input (RxD0) pin is selected as the input for the external interrupt (INTP0) and therefore passes
The INTP0 interrupt detects the wake-up signal.
If bit1 is set to 1, the input signal from the serial data input (RxD0) pin is selected as the input to the timer,
so that the wake-up signal can be detected by the timer and the low-level width of the interval segment and the
pulse width of the synchronization segment can be measured.
The SS1E00 bit controls the SS00 pin input of channel 0 in slave mode of SSPI00 communication. During
the period when the SS00 pin is input high, no transmission and reception occurs even if the serial clock is input;
During the low input level to the SS00 pin, if a serial clock is entered, it is transmitted and received according to
the settings of each mode.
The ISC register is set via an 8-bit memory operation command.
After the reset signal is generated, the value of the ISC register changes to 00H.
Figure 12-19 Format of input switching control register (ISC)
Address: 40040473H After reset: 00HR/W
Symbol
7 6 5 4 3 2 1
0
ISC
SSDIE00
Setting of SS00 input of channel 0 in slave mode for SSPI00 communication
0
The SS00 pin input is invalid.
1
The SS00 pin input is valid.
ISC1
Input switching of channel 3 of timer Timer4
0
Use the input signal from the TI03 pin as the input to the timer (usually running).
1
Use the input signal from the RxD0 pin as the input to the timer (detects the wake-up signal
and measures the low-level width of the interval and the pulse width of the sync field).
ISC0
Input switching for external interrupt (INTP0)
0
Use the input signal from the INTP0 pin as the input for an external interrupt (usually in
operation).
1
Use the input signal from the RxD0 pin as the input for the external interrupt (detect wake-up
signal).
Note Bit6~0 must be set to 0.
SYESE00
0
0
0
0
0
ISC1
ISC0