
336 c ~ A P~ ~i ~ ~5 Square Root by Digit Recurrence
K REGISTER
I
LOAD/APPEND
F GENERATOR
F[j]
I
LOAD/APPEND
B REGISTER
FIGURE 6.2
Network for generating F. (Adapted from (Ercegovac and Lang, 1990).)
Overall Algorithm, Implementation, and Timing
The overall algorithm is shown in Figure 6.3 and its implementation at the block-
diagram level in Figure 6.4. The cycle time is
Tcycle =
tSEL + tF-CEX + tADD + tload
6.21
(5,,,$.
1
Examples of Implementations
We now describe two example implementations, one radix-2 and one radix-4.
The corresponding selection functions are derived in Section
6.6.
Radix-2 Square Root with Carry-Save Adder ...