EP3SE50F780I3N Altera, EP3SE50F780I3N Datasheet - Page 137

• Manufacturer Part Number: EP3SE50F780I3N
• Description: Stratix III
• Manufacturer: Altera

Altera Corporation
October 2007
Two saturation modes are supported in Stratix III:
■
■
You must select one of the two options at compile time.
Table 5–6. Example of Round-To-Nearest-Even Mode
Table 5–7. Comparison of Round-to-Nearest-Integer and
Round-to-Nearest-Even
6- to 4-bits
Rounding
Asymmetric saturation mode
Symmetric saturation mode
010111
001101
001010
001110
110111
101101
110110
110010
Round-To-Nearest-Integer
010111
001101
001010
001110
110111
101101
110110
110010
⇒
⇒
⇒
⇒
⇒
⇒
⇒
⇒
Even (0010)
Even (1100)
Odd (0011)
Odd (1101)
Odd/Even
(Integer)
0110
0011
0011
0100
1110
1011
1110
1101
x
x
x
x
Fractional
> 0.5 (11)
< 0.5 (01)
= 0.5 (10)
= 0.5 (10)
> 0.5 (11)
< 0.5 (01)
= 0.5 (10)
= 0.5 (10)
Stratix III Device Handbook, Volume 1
DSP Blocks in Stratix III Devices
Round-To-Nearest-Even
010111
001101
001010
001110
110111
101101
110110
110010
Integer
Add to
1
0
0
1
1
0
1
0
⇒
⇒
⇒
⇒
⇒
⇒
⇒
⇒
0110
0011
0010
0100
1110
1011
1110
1100
Result
0110
0011
0010
0100
1110
1011
1110
1100
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