at94k10al ATMEL Corporation, at94k10al Datasheet - Page 121

• Manufacturer Part Number: at94k10al
• Description: At94k05al 5k - 40k Gates Of At40k Fpga With 8-bit Microcontroller, Up To 36k Bytes Of Sram And On-chip Jtag Ice
• Manufacturer: ATMEL Corporation

4.28.7
4.28.7.1
1138I–FPSLI–1/08
Implementations
mul16x16_16
The registers R19:R18:R17:R16 will be incremented with the result of the multiplication of
0.771484375 with the ADC conversion result. In this example, the ADC result is treated as a
signed fraction number. We could also treat it as a signed integer and call it “mac16x16_32”
instead of “fmac16x16_32”. In this case, the 0.771484375 should be replaced with an integer.
Description
Usage
Statistics
Note:
Multiply of two 16-bit numbers with a 16-bit result.
R17:R16 = R23:R22 • R21:R20
Cycles: 9 + ret
Words: 6 + ret
Register usage: R0, R1 and R16 to R23 (8 registers)
mul16x16_16:
mul
movw
mul
add
mul
add
ret
1. Full orthogonality, i.e., any register pair can be used as long as the result and the two oper-
ands do not share register pairs. The routine is non-destructive to the operands.
r22, r20
r17:r16, r1:r0
r23, r20
r17, r0
r21, r22
r17, r0
; al * bl
; ah * bl
; bh * al
AT94KAL Series FPSLIC
(1)
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