ST72141K Datasheet, PDF (38/132 Pages) STMicroelectronics – 8-BIT MCU WITH ELECTRIC-MOTOR CONTROL, ADC, 16-BIT TIMERS, SPI INTERFACE

ST72141K
7 MISCELLANEOUS REGISTER
The miscellaneous register allows control over
several different features such as the external in-
terrupts or the I/O alternate functions.
7.1 I/O Port Interrupt Sensitivity Description
The external interrupt sensitivity is controlled by
the ISxx bits of the Miscellaneous register. This
control allows to have two fully independent exter-
nal interrupt source sensitivities as shown in Fig-
ure 25.
Each external interrupt source can be generated
on four different events on the pin:
s Falling edge
s Rising edge
s Falling and rising edge
s Falling edge and low level
To guaranty correct functionality, a modification of
the sensitivity in the MISCR register must be done
only when the I bit of the CC register is set to 1 (in-
terrupt masked). See I/O port register and Miscel-
laneous register descriptions for more details on
the programming.
Figure 25. External Interrupt Sensitivity
7.2 I/O Port Alternate Functions
The MISCR register manages the SPI SS pin al-
ternate function configuration. This makes it possi-
ble to use the PB2 I/O port function while the SPI is
active.
These functions are described in detail in Section
7.4 Miscellaneous Register Description.
7.3 Clock Prescaler Selection
The MISCR register is used to select the SLOW
mode (see Section 5.4 SLOW Mode for more de-
tails) and the SPI and Motor Control peripheral
clock prescaler.
MISCR
IS01 IS00
EI0
INTERRUPT
PA7
SENSITIVITY
SOURCE
CONTROL
PA0
MISCR
IS11 IS10
EI1
INTERRUPT
PB7
SENSITIVITY
SOURCE
CONTROL
PB0
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