Fujitsu MB91260B Series Hardware Manual page 380

[bit11] RND (Rounding)
This bit specifies whether to perform rounding for 16-bit data specified by the SLQ bits.
Rounding rounds the 16-bit data based on the bit immediately below the LSB (round up if lower bit is "1",
ignore if "0").
[bit10] CLP (Clipping)
This bit specifies whether to perform saturation processing on the 16-bit data value specified by the SLQ
bits if the calculation result in the accumulator represents an overflow in the 16-bit value.
In practice, saturation processing is performed if the MSB of the accumulator (bit39) is different to the
MSB of the 16-bit value (determined by the SLQ bits). If rounding is enabled, the comparison is performed
using the result after rounding.
The value transferred to data RAM is the maximum positive value ("7FFF
accumulator was positive before rounding, or the maximum negative value ("8000
Rounding and saturation processing does not change the sign of the accumulator.
[bit9 to bit7] SLQ
Specifies which bits of the accumulator to transfer to data RAM.
SLQ Bit Overflow Judging Bit
0 0 0 bit39 to bit27
0 0 1 bit39 to bit28
0 1 0 bit39 to bit29
0 1 1 bit39 to bit30
1 0 0 bit39 to bit23
1 0 1 bit39 to bit24
1 1 0 bit39 to bit25
1 1 1 bit39 to bit26
[bit6] SLY
Specifies the transfer destination.
0: X-RAM
1: Y-RAM
[bit5 to bit0] X/Y Addr (RAM Address)
Specifying direct addressing for data RAM
CHAPTER 15 MULTIPLICATION AND ADDITION CALCULATOR
Transfer 16-bit
Data
bit27 to bit12
bit28 to bit13
bit29 to bit14
bit30 to bit15
bit23 to bit8
bit24 to bit9
bit25 to bit10
bit26 to bit11
") if the value of the
H
") if negative.
H
Rounding Fixed-point
Bit Decimal Format
bit11 Q12
bit12 Q13
bit13 Q14
bit14 Q15
bit7 Q8
bit8 Q9
bit9 Q10
bit10 Q11
365