MCBSTM32EXL Keil, MCBSTM32EXL Datasheet - Page 345

• Manufacturer Part Number: MCBSTM32EXL
• Description: BOARD EVALUATION FOR STM32F103ZE
• Manufacturer: Keil

Specifications of MCBSTM32EXL

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

RM0008
Table 75.
An external incremental encoder can be connected directly to the MCU without external
interface logic. However, comparators are normally be used to convert the encoder’s
differential outputs to digital signals. This greatly increases noise immunity. The third
encoder output which indicate the mechanical zero position, may be connected to an
external interrupt input and trigger a counter reset.
The
direction control. It also shows how input jitter is compensated where both edges are
selected. This might occur if the sensor is positioned near to one of the switching points. For
this example we assume that the configuration is the following:
●
●
●
●
●
●
Figure 133. Example of counter operation in encoder interface mode.
Figure 134
configuration as above except CC1P=’1’).
Active edge
Counting on
Counting on
Counting on
TI1 and TI2
TI1 only
TI2 only
Figure 133
CC1S=’01’ (TIMx_CCMR1 register, IC1FP1 mapped on TI1).
CC2S=’01’ (TIMx_CCMR2 register, IC2FP2 mapped on TI2).
CC1P=’0’ (TIMx_CCER register, IC1FP1 non-inverted, IC1FP1=TI1).
CC2P=’0’ (TIMx_CCER register, IC2FP2 non-inverted, IC2FP2=TI2).
SMS=’011’ (TIMx_SMCR register, both inputs are active on both rising and falling
edges).
CEN=’1’ (TIMx_CR1 register, Counter is enabled).
Counter
TI2
TI1
gives an example of counter behavior when IC1FP1 polarity is inverted (same
Counting direction versus encoder signals
gives an example of counter operation, showing count signal generation and
TI2, TI2FP2 for TI1)
Level on opposite
signal (TI1FP1 for
forward
High
High
High
Low
Low
Low
up
Doc ID 13902 Rev 9
jitter
No Count
No Count
Rising
Down
Down
down
Up
Up
backward
TI1FP1 signal
No Count
No Count
Falling
Down
Down
Up
Up
jitter
General-purpose timer (TIMx)
No Count
No Count
Rising
Down
Down
Up
Up
forward
TI2FP2 signal
up
No Count
No Count
Falling
Down
Down
Up
Up
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