Holtek BS83A04C, Руководство пользователя

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Rev. 1.00 48 March 24, 2020 Rev. 1.00 49 March 24, 2020
BS83A04C
4-Key Enhanced Touch I/O Flash MCU
BS83A04C
4-Key Enhanced Touch I/O Flash MCU
• 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 select when low voltage power supply
0: All pin pull high resistor is 60kΩ @ 3V
1: All pin pull high resistor is 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 SLEEP or IDLE Mode.
• PAWU Register
Bit 7 6 5 4 3 2 1 0
Name PAWU7 PAWU6 PAWU5 PAWU4 PAWU3 PAWU2 PAWU1 PAWU0
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
Bit 7~0 PAWU7~PAWU0 : PA7~PA0 wake-up function control
0: Disable
1: Enable
I/O Port Control Registers
I/O port has a control register known as PAC, to control the input/output configuration. With this
control register, each CMOS output or input can be reconfigured dynamically under software
control. Each pin of the I/O ports is directly mapped to a bit in its associated port control register.
For the I/O pin to function as an input, the corresponding bit of the control register must be written
as a “1”. This will then allow the logic state of the input pin to be directly read by instructions.
When the corresponding bit of the control register is written as a “0”, the I/O pin will be setup as
a CMOS output. If the pin is currently setup as an output, instructions can still be used to read the
output register. However, it should be noted that the program will in fact only read the status of the
output data latch and not the actual logic status of the output pin.