STC micro STC8A8K64D4 Series - MDU16 Hardware 16-Bit Multiplier and Divider; Registers Related to MDU16; Operand 1 Data Registers (MD0~MD3); Operand 2 Data Registers (MD4~MD5)

STC8A8K64D4 Series Manual
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25 MDU16 Hardware 16-bit Multiplier and Divider
A 16-bit hardware multiply / divide unit MDU16 is integrated in some microcontrollers of the STC8A8K64D4 series.
The following data operations are supported:
➢ Data standardization (need 3-20 clocks of computing time)
➢ Logic left shift (need 3～18 clocks of operation time)
➢ Logic shift right (need 3～18 clocks of operation time)
➢ 16 bits multiplied by 16 bits (it takes 10 clocks of operation time)
➢ 16 bits divided by 16 bits (need 9 clocks of operation time)
➢ 32 bits divided by 16 bits (requires 17 clocks of operation time)
All operations are based on unsigned integer data types.
25.1 Registers Related to MDU16
Symbol
Description
Address
Bit Address and Symbol
Reset
Value
B7
B6
B5
B4
B3
B2
B1
B0
MD3
MDU Data Register
FCF0H
MD3[7:0]
0000,0000
MD2
MDU Data Register
FCF1H
MD2[7:0]
0000,0000
MD1
MDU Data Register
FCF2H
MD1[7:0]
0000,0000
MD0
MDU Data Register
FCF3H
MD0[7:0]
0000,0000
MD5
MDU Data Register
FCF4H
MD5[7:0]
0000,0000
MD4
MDU Data Register
FCF5H
MD4[7:0]
0000,0000
ARCON
MDU Mode Control Register
FCF6H
MODE[2:0]
SC[4:0]
0000,0000
OPCON
MDU Operation Control Register
FCF7H
-
MDOV
-
-
-
-
RST
ENOP
0000,0000
25.1.1 Operand 1 Data Registers (MD0~MD3)
Symbol
Address
B7
B6
B5
B4
B3
B2
B1
B0
MD3
FCF0H
MD3[7:0]
MD2
FCF1H
MD2[7:0]
MD1
FCF2H
MD1[7:0]
MD0
FCF3H
MD0[7:0]
25.1.2 Operand 2 Data Registers (MD4~MD5)
Symbol
Address
B7
B6
B5
B4
B3
B2
B1
B0
MD5
FCF4H
MD5[7:0]
MD4
FCF5H
MD4[7:0]
32-bit division by 16-bit division:
Dividend: {MD3,MD2,MD1,MD0}
Divisor: {MD5,MD4}
Quotient: {MD3,MD2,MD1,MD0}
Remainder: {MD5,MD4}
16-bit division by 16-bit division:
Dividend: {MD1,MD0}
Divisor: {MD5,MD4}
Quotient: {MD1,MD0}
Remainder: {MD5,MD4}
16-bit multiplication by 16-bit multiplication:
Multiplicand: {MD1,MD0}