Rev. 1.00
166
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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
MDU1Rn Register – n=0~5
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
x
x
x
x
x
x
x
x
"x": �nknown
Bit 7~0
D7~D0
: 16-bit MDU1 data register n
MDU1CTRL Register
Bit
7
6
5
4
3
2
1
0
Name
MD1EF
MD1OV
—
—
—
—
—
—
R/W
R
R
—
—
—
—
—
—
POR
0
0
—
—
—
—
—
—
Bit 7
MD1EF
: 16-bit MDU1 error flag
0: Normal
1:
Abnormal
This bit will be set to 1 if the data register MDU1Rn is written or read as the MDU1
operation is executing. This bit should be cleared to 0 by reading the MDU1CTRL
register if it is equal to 1 and the MDU1 operation is completed.
Bit 6
MD1OV
: 16-bit MDU1 overflow flag
0: No overflow occurs
1:
Multiplication product > FFFFH or Divisor=0
When an operation is completed, this bit will be updated by hardware to a new value
corresponding to the current operation situation.
Bit 5~0
Unimplemented, read as "0"
MDU Operation
The 8-bit MDU0 operation and the 16-bit MDU1 operation are carried out in their own specific way
and will be introduced separately.
8-bit MDU0 Operation
For this MDU the multiplication or division operation is carried out in a specific way and is
determined by the MD0S bit in the MDU0CTRL register. Before a multiplication or division
operation starts, write the multiplicand/dividend into the MDU0R0 register and the multiplier/
divisor into the MDU0R1 register. After the multiplication or division operation is completed, the
MDU0R0 register stores the multiplication product low byte or the division quotient, the MDU0R1
register stores the multiplication product high byte or the division remainder. All MDU0 operations
will be executed after the MDU0CTRL register is write-accessed. The necessary calculation time
for one MDU0 operation, either multiplication or division, is 4 ×
t
SYS
. After the completion of each
operation, it is necessary to check the operation status in the MDU0CTRL register to make sure that
whether the operation is completed or not and correct or not.
The overall important points for the MDU0 read/write access and calculation time are summarised
in the following table.
Operations
Items
8-bit / 8-bit Division
8-bit × 8-bit Multiplication
Write Access
Dividend written to MDU0R0
Divisor written to MDU0R1
M�ltiplicand written to MDU0R0
M�ltiplier written to MDU0R1
Calc�lation Time
4 × t
SYS
4 × t
SYS
Read Access
Q�otient read from MDU0R0
Remainder read from MDU0R1
Prod�ct Low Byte read from MDU0R0
Prod�ct High Byte read from MDU0R1
8-Bit MDU0 Operations Summary