Rev. 1.00
100
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Rev. 1.00
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HT66FM5440
Brushless DC Motor A/D Flash MCU
HT66FM5440
Brushless DC Motor A/D Flash MCU
• ADDL Register
Bit
7
6
5
4
3
2
1
0
Name
D�
D6
D5
D4
D3
D�
D1
D0
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
D7~D0
: A/D delay time register bit 7 ~ bit 0 (count by f
SYS
)
A/D delay time value=(1/f
SYS
) × ADDL[7:0]
• ADBYPS Register
Bit
7
6
5
4
3
2
1
0
Name
UGB_ON
—
BYPSAN� BYPSAN6 BYPSAN3 BYPSAN� BYPSAN1 BYPSAN0
R/W
R/W
—
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
—
0
0
0
0
0
0
Bit 7
UGB_ON
: Unity-gain buffer on/off control
0: Disable
1: Enable
Bit 6
Unimplemented, read as "0"
Bit 5
BYPSAN7
: AN7 bypass unity-gain buffer control
0: Disable, AN7 go through unity-gain buffer
1: Enable, AN7 bypass unity-gain buffer
Bit 4
BYPSAN6
: AN6 bypass unity-gain buffer control
0: Disable, AN6 go through unity-gain buffer
1: Enable, AN6 bypass unity-gain buffer
Bit 3
BYPSAN3
: AN3 bypass unity-gain buffer control
0: Disable, AN3 go through unity-gain buffer
1: Enable, AN3 bypass unity-gain buffer
Bit 2
BYPSAN2
: AN2 bypass unity-gain buffer control
0: Disable, AN2 go through unity-gain buffer
1: Enable, AN2 bypass unity-gain buffer
Bit 1
BYPSAN1
: AN1 bypass unity-gain buffer control
0: Disable, AN1 go through unity-gain buffer
1: Enable, AN1 bypass unity-gain buffer
Bit 0
BYPSAN0
: AN0 bypass unity-gain buffer control
0: Disable, AN0 go through unity-gain buffer
1: Enable, AN0 bypass unity-gain buffer
A/D Converter Operation
There are two ways to initiate an A/D converter conversion cycle. The first of these is to use the
ADSTR bit in the ADCR0 register to start and reset the AD converter. When the microcontroller sets
this bit from low to high and then low again, an analog to digital conversion cycle will be initiated.
When the ADSTR bit is brough from low to high but not low again, the EOCB bit in the ADCR0
register will be set high and the analog to digital converter will be reset.
The second method of initiating a conversion is to use the PWM interrupt signal to trigger the A/
D auto-scan which is enabled by the DLSTR bit in the ADCR1 register. The PWM interrupt signal
can be sourced from either the PWM period or the PWM duty interrupt signal, selected using the
PWIS bit. If selects PWM duty interrupt signal, the actual PWM duty interrupt trigger source can be
selected by the PWDIS1 and PWDIS0 bits in the ADCR2 register. The DLSTR bit can also activate
a delay function which inserts a delay time between the incoming PWM interrupt signal and the
actual start of the A/D conversion process, with the actual time being setup using the ADDL register.
The actual delay time is calculated by the register content multiplied by the system clock period.
The delay time is used to reduce the possibility of erroneous analog samples being taken during the
time of large transient current swithing by the motor drive tansistors.