Visible to Intel only — GUID: sam1403481527051
Ixiasoft
Visible to Intel only — GUID: sam1403481527051
Ixiasoft
3.4.7. Accumulator and Chainout Adder for Fixed-Point Arithmetic
The Intel® Cyclone® 10 GX variable precision DSP block supports a 64-bit accumulator and a 64-bit adder for fixed-point arithmetic.
The following signals can dynamically control the function of the accumulator:
- NEGATE
- LOADCONST
- ACCUMULATE
The accumulator supports double accumulation by enabling the 64-bit double accumulation registers located between the output register bank and the accumulator.
The accumulator and chainout adder features are not supported in two fixed-point arithmetic independent 18 x 19 modes.
Function | Description | NEGATE | LOADCONST | ACCUMULATE |
---|---|---|---|---|
Zeroing | Disables the accumulator. | 0 | 0 | 0 |
Preload | The result is always added to the preload value. Only one bit of the 64-bit preload value can be “1”. It can be used as rounding the DSP result to any position of the 64-bit result. | 0 | 1 | 0 |
Accumulation | Adds the current result to the previous accumulate result. | 0 | X | 1 |
Decimation + Accumulate | This function takes the current result, converts it into two’s complement, and adds it to the previous result. | 1 | X | 1 |
Decimation + Chainout Adder | This function takes the current result, converts it into two’s complement, and adds it to the output of previous DSP block. | 1 | 0 | 0 |