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S E R I A L C O N T R O L M O D U L E : U A R T
ARM wakeup on character recognition
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character completes, regardless of any flow control mechanism that might stall
normal data transmission.
Use the Force Transmit Character Control register to program this operation.
Force character
transmission
procedure
These steps outline a single force character transmission operation:
1
Read the Force Transmit Character Control register and verify that the ENABLE
field is 0. The Force Transmit Character Control register must not be written
while the ENABLE field is 1.
2
Write a 1 to the ENABLE field and the required character to the CHAR field. This
operation can be a single step.
Collecting
feedback
Force character transmission completion status is available. It is up to you as to
whether you want to collect feedback. If you do want to collect feedback, these are
your options:
Poll the ENABLE field in the Force Transmit Character Control register until it
reads 0.
Poll the FORCE field in the Interrupt Status register until it reads 1.
Enable the FORCE interrupt by writing a 1 to the FORCE field in the Interrupt
Enable register and servicing the interrupt when it occurs.
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A R M w a k e u p o n c h a r a c t e r r e c o g n i t i o n
The UART module provides a signal to the SCM module that can wake up the ARM
processor. This signal is asserted when a specified character is received. Use the
Receive Character Match Control registers and the ARM Wakeup Control register to
implement the logic.
Example
configuration
This table shows a sample configuration where the wakeup signal is asserted on
reception of any character:
Control register
Field
Value
Comment
Receive Character Match Control
Register 0
ENABLE
1
Enable character match
MASK
0xff
Mask all bits
DATA
0x00
Don’t care
ARM Wakeup Control register
ENABLE
1
Enable the function
Summary of Contents for NS9215
Page 1: ...NS9215 Hardware Reference 90000847_C Release date 10 April 2008...
Page 3: ......
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Page 26: ...26 Hardware Reference NS9215...
Page 44: ...P I N O U T 26 5 System clock 44 Hardware Reference NS9215 System clock drawing...
Page 52: ...P I N O U T 26 5 Power and ground 52 Hardware Reference NS9215...
Page 80: ...I O C O N T ROL M O D U L E Memory Bus Configuration register 80 Hardware Reference NS9215...
Page 136: ...WOR KI N G W I TH T H E C P U Noncachable instruction fetches 136 Hardware Reference NS9215...
Page 202: ...S Y S T E M C O N T RO L M OD U L E RTC Module Control register 202 Hardware Reference NS9215...
Page 354: ...E X T E R N A L D M A DMA Peripheral Chip Select register 354 Hardware Reference NS9215...
Page 472: ...R E A L TI M E C L O C K M O D U L E General Status register 472 Hardware Reference NS9215...
Page 512: ...TI M I NG Clock timing 512 Hardware Reference NS9215...
Page 515: ...PA CKA GING Processor Dimensions www digiembedded com 515...
Page 516: ...PA CKA GING Processor Dimensions 516 Hardware Reference NS9215...