Variable Precision DSP Blocks User Guide: Agilex™ 5 FPGAs and SoCs

ID 813968
Date 9/20/2024
Public
Document Table of Contents

5.6.3. 18 × 18 Full Mode Signals

Figure 68. 18 × 18 Full Mode Signals


Table 64.  Data Input and Output Signals
Signal Name Type Width Description
ax[17:0] Input 18 Input data bus to top multiplier.

This signal is not available when internal coefficient feature is enabled.

ay[18:0] Input 19 Input data bus to top multiplier.

When pre-adder is enabled, these signals are served as input to the top pre-adder.

az[17:0] Input 18

These signal are input to the top pre-adder.

These signals are only available when pre-adder is enabled.

bx[17:0] Input 18 Input data bus to bottom multiplier.
by[18:0] Input 19 Input data bus to bottom multiplier.

When pre-adder is enabled, these signals serve as input signals to the bottom pre-adder.

bz[17:0] Input 18

These signals are input signals to the bottom pre-adder.

These signals are only available when pre-adder is enabled.

resulta[36:0] Output 37 Output data bus from top multiplier.
resultb[36:0] Output 37 Output data bus from bottom multiplier.
Table 65.  Clock, Enable, and Clear Signals
Signal Name Type Width Description
clk[0] Input 1 Input clock for all registers.
ena[2:0] Input 3 Clock enable signals for all registers.

Clock enable signals have higher priority compared to the SCLR signals.

These signals are active-High.

clr[1:0] Input 2 These signals can be asynchronous or synchronous clear input signals for all registers. You may select the type of clear input signal using Type of clear signal parameter.

These signals are active-High.

By default, this signal is low.

For more information about clock enable restrictions for input registers, refer to the related information.

Table 66.  Dynamic Control SignalFor a summary of supported dynamic control features for each operational mode, refer to the related information.
Signal Name Type Width Description
disable_scanin Input 1 Dynamic input signal to enable dynamic scanin feature. You can change the value of this signal during run-time.

This signal is available when you Set Enable 'disable scanin parameter to Yes.

You must set Enable input cascade for 'ay' input parameter to Yes to use this signal.

  • 0: Switch the input of the top multiplier to use scanin input.
  • 1: Switch the input of the top multiplier to use ay input.
Table 67.  Internal Coefficient PortsFor a summary of supported features for each operational mode, refer to the related information.
Signal Name Type Width Description
coefsela[2:0] Input 3 Input selection signals for 8 coefficient values defined by user for the top multiplier. The coefficient values are stored in the internal memory and specified by parameters coef_a_0 to coef_a_7.
  • coefsela[2:0] = 000 refers to coef_a_0
  • coefsela[2:0] = 001 refers to coef_a_1
  • coelsela[2:0] = 010 refers to coef_a_2 and so forth.

These signals are only available when the internal coefficient feature is enabled.

coefselb[2:0] Input 3 Input selection signals for 8 coefficient values defined by user for the bottom multiplier. The coefficient values are stored in the internal memory and specified by parameters coef_b_0 to coef_b_7.
  • coefselb[2:0] = 000 refers to coef_b_0
  • coefselb[2:0] = 001 refers to coef_b_1
  • coelselb[2:0] = 010 refers to coef_b_2 and so forth.

These signals are only available when the internal coefficient feature is enabled.

Table 68.  Input Cascade Signals
Signal Name Type Width Description
scanin[26:0] Input 27 Input data bus for input cascade module.

Connect these signals to the scanout signals from the preceding DSP core.

scanout[26:0] Output 27 Output data bus of the input cascade module.

Connect these signals to the scanin signals of the next DSP core.