Scicos Block
fr - eng

Left shift circulate integer modulo function block





This block realizes a left shift circulate integer modulo function. The output is the left shift circulate N bit of the input word, define by a length of Nbit bits using the 2 complement arithmetic notation. Then, the values of the output are comprise between $ \left[-2^{Nbit-1};2^{Nbit-1}-1\right]$.
This function is described by a nonconstant amplitude. Following the number of shift, this nonlinearity takes different slope. Fig.1 shows an example for a given length (Nbit=5), for one shift and two shift.

Figure 1: Nonlinear function lcmodulo for Nbit=5. (a) One shift; (b) Two shifts

This function is modelled with binary operators of C language. First block begins to convert input value, in an unsigned integer value. After it realizes N times the left shift. Table.1 shows necessary stages to realize this operation for an integer value defined by a length of 8 bits.

Table 1: Computation stages of the left binary shift circulate operation
Stages Operations Decimal Binary
1 Read unsigned integer value 150 1001 0110
2 Left shift binary 300 1 0010 1100
3 Tronquate to 8 bits 44 0010 1100
4 Addition of the tronquate bits 45 0010 1101

Computational function finally converts unsigned integer value in signed integer value and puts results in output register y.

Dialog box


Default properties

Interfacing function

Computational function

See also


A. Layec