SM39A16M1
8-Bit Micro-controller
16KB with ISP Flash
& 1K+256B RAM embedded
6.2.2 Second phase: Executing calculation.
During executing operation, the MDU works on its own parallel to the CPU. When MDU is finished, the MDUF register
will be set to one by hardware and the flag will clear at next calculation.
Mnemonic: PCON
Address: 87h
7
6
5
4
-
3
-
2
-
1
0
IDLE
Reset
40H
SMOD
MDUF
-
STOP
MDUF: MDU finish flag.
When MDU is finished, the MDUF will be set by hardware and the bit will clear by
hardware at next calculation.
Table 6-3 MDU execution times
Operation
Number of Tclk
Division 32bit/16bit
Division 16bit/16bit
17 clock cycles
9 clock cycles
11 clock cycles
Multiplication
Shift
min 3 clock cycles , max 18 clock cycles
min 4 clock cycles , max 19 clock cycles
Normalize
6.2.3 Third phase: Reading the result from the MDx registers.
Read out sequence of the first MDx registers is not critical but the last read (from MD5 - division and MD3 -
multiplication, shift and normalizing) determines the end of a whole calculation (end of phase three).
Table 6-4 MDU registers read sequence
Operation
32Bit/16Bit
MD0 Quotient Low
MD1 Quotient
16Bit/16Bit
MD0 Quotien Low
MD1 Quotien High
16Bit x 16Bit
MD0 Product Low
MD1 Product
shift/normalizing
MD0 LSB
MD1
First read
MD2 Quotient
MD2 Product
MD2
MD3 Quotient High
MD4 Remainder L
MD5 Remainder H
MD4 Remainder Low
MD5 Remainder High
Last read
MD3 Product High
MD3 MSB
6.3 Normalizing
All reading zeroes of integers variables in registers MD0 to MD3 are removed by shift left operations. The whole
operation is completed when the MSB (most significant bit) of MD3 register contains a ‟1‟. After normalizing, bits
ARCON.4 (MSB) to ARCON.0 (LSB) contain the number of shift left operations, which were done.
6.4 Shifting
SLR bit (ARCON.5) has to contain the shift direction, and ARCON.4 to ARCON.0 the shift count (which must not be 0).
During shift, zeroes come into the left or right end of the registers MD0 or MD3, respectively.
Specifications subject to change without notice contact your sales representatives for the most recent information.
ISSFD-M069
Ver C SM39A16M1 7/31/2013
- 34 -
SYNCMOS [ SYNCMOS TECHNOLOGIES,INC ]
