Rev. 1.10
82
October 23, 2020
Rev. 1.10
83
October 23, 2020
BC66F5652
2.4GHz RF Transceiver A/D Flash MCU
BC66F5652
2.4GHz RF Transceiver A/D Flash MCU
to determine whether the pull-high function is enabled or not while the LVPUC register is used to
select the pull-high resistors value for low voltage power supply applications.
Note that the pull-high resistor can be controlled by the relevant pull-high control register only when
the pin-shared functional pin is selected as an digital input or NMOS output. Otherwise, the pull-
high resistors can not be enabled.
• PxPU Register
Bit
7
6
5
4
3
2
1
0
Name
PxPU7
PxPU6
PxPU5
PxPU4
PxPU3
PxPU2
PxPU1
PxPU0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
PxPUn
: I/O Port x Pin pull-high function control
0: Disable
1: Enable
The PxPUn bit is used to control the pin pull-high function. Here the “x” can be A, B, C or D.
However, the actual available bits for each I/O Port may be different.
Special attention has to be paid to the line, PA1, which should be set as output or if set as
input must have pull-high resistor connected to avoid unwanted power consumption result
from floating input conditions. For the PC3~PC6 lines, which are internally connected
to the RF transceiver lines, the corresponding PCPU3~PCPU6 bits in the PCPU register
should be properly configured after power on.
• LVPUC Register
Bit
7
6
5
4
3
2
1
0
Name
—
—
—
—
—
—
—
LVPU
R/W
—
—
—
—
—
—
—
R/W
POR
—
—
—
—
—
—
—
0
Bit 7~1
Unimplemented, read as “0”
Bit 0
LVPU
: Pull-high resistor selection when low voltage power supply
0: All pin pull-high resistors are 60kΩ @ 3V
1: All pin pull-high resistors are 15kΩ @ 3V
This bit is used to select the pull-high resistor value for low voltage power supply
applications. The LVPU bit is only available when the corresponding pin pull-high
function is enabled by setting the relevant pull-high control bit high. This bit will have
no effect when the pull-high function is disabled.
Port A Wake-up
The HALT instruction forces the microcontroller into the SLEEP or IDLE Mode which preserves
power, a feature that is important for battery and other low-power applications. Various methods
exist to wake-up the microcontroller, one of which is to change the logic condition on one of the Port
A pins from high to low. This function is especially suitable for applications that can be woken up
via external switches. Each pin on Port A can be selected individually to have this wake-up feature
using the PAWU register.
Note that the wake-up function can be controlled by the wake-up control registers only when the pin
is selected as a general purpose input and the MCU enters the IDLE or SLEEP mode.