Notes: Cyclone IV Vol. 1 Chapter 4 embedded multiplier in the cyclone IV Device

An embedded multiplier can be configured as an 18 × 18 multiplier or two 9 × 9 multiplier. For multiplication operations greater than 18 × 18, Quartus II software cascade multiple embedded multiplier modules. Although there is no limit on the Data Bit Width of the multiplier, the larger the data bit width, the slower the multiplication operation.

 

In addition to the embedded multiplier in the cyclone IV device, you can use the m9k memory module as the LUT to implement the soft multiplier.

 

Based on the operation mode of the multiplier, you can connect each multiplier input signal to the input register, you can separately set whether each input of the multiplier uses the input register.

Based on the data width or operation mode of the multiplier, a single embedded multiplier can execute one or two multiplication operations at the same time.

The signal between signa and signb controls the input of the multiplier and determines whether the value is signed or unsigned. If the SIGNA signal is high, the data a operand is a signed value. Conversely, the data a operand is an unsigned value. If any operand is a signed number, the result of the product is a signed number.

 

If the embedded multiplier has two 9x9 multiplier, the data a input and data B input of the two multiplier will share the same signa signal and the same signb signal respectively. You can dynamically change the SIGNA and signb signals at runtime to modify the Symbol Representation of input operands. You can send signa and signb through a dedicated input register. No matter what the symbol represents, the multiplier supports full precision.

When the SIGNA and signb signals are not used, Quartus II sets the multiplier to perform the unsigned Multiplication operation by default.

 

The embedded multiplier of the cyclone IV device can implement the multiplier and multiplier functions. The multiplier of this function is implemented by the embedded multiplier, while the multiplier or the accumulator function is in the logical unit (LE).

In addition, you can dynamically modify signa and signb signals and send these signals through dedicated input registers.

All data a input data used to drive the same embedded multiplier must have the same symbol representation. Similarly, all data B input data used to drive the same embedded multiplier must have the same symbol representation.

 

Notes: Cyclone IV Vol. 1 Chapter 4 embedded multiplier in the cyclone IV Device