Variable Precision DSP Blocks User Guide: Agilex™ 5 FPGAs and SoCs
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5.5.5. Accumulator/Output Chaining
| Parameter | IP Generated Parameter | Value | Default Value | Description | 
|---|---|---|---|---|
| Accumulator | ||||
| Enable accumulate port | enable_accumulate | No Yes | No | Select to enable accumulate port. 
         Only available for the following operational modes: 
          
 | 
| Enable 'accumulate' input register | accumulate_clken | no_reg ena0 ena1 ena2 | no_reg | Specify the clock enable signal for accumulate input register. 
         Only available for the following operational modes: 
          
 For more information about clock enable restrictions for input registers, refer to the related information. | 
| Enable double accumulator | enable_double_accum | No Yes | No | Select to enable the double accumulator feature. 
         Only available for the following operational modes: 
          
 | 
| Negate | ||||
| Enable 'negate' port | enable_negate | No Yes | No | Select to enable negate port. 
         Only available for the following operational modes: 
          
 | 
| Enable 'negate' input register | negate_clken | no_reg ena0 ena1 ena2 | no_reg | Specify the clock enable signal for negate input register. 
         Only available for the following operational modes: 
          
 For more information about clock enable restrictions for input registers, refer to the related information. | 
| Enable 'negate systolic' register | negate_systolic_reg | no_reg ena0 ena1 ena2 | no_reg | Only supported in m18x18_systolic mode. Must be enabled when "negate" port is used. | 
| Loadconst | ||||
| Enable 'loadconst' port | enable_loadconst | No Yes | No | Select to enable loadconst port. 
         Only available for the following operation modes: 
          
 | 
| Enable 'loadconst' input register | load_const_clken | no_reg ena0 ena1 ena2 | no_reg | Specify the clock enable signal for loadconst input register. 
         Only available for the following operation modes: 
          
 For more information about clock enable restrictions for input registers, refer to the related information. | 
| N value of preset constant | load_const_value | 0–63 | 0 | Specify the preset constant value. This value can be 2N where N is the preset constant value. 
         Only available for the following operation modes: 
          
 | 
| Chainin/Chainout | ||||
| Enable chainin port | use_chainadder | No Yes | No | Select to enable chainin port. 
         Only available for the following operation modes: 
          
 | 
| Enable chainout port | enable_chainout | No Yes | No | Select to enable chainout port. 
         Only available for the following operation modes: 
          
 | 
| Enable disable_chainout | disable_chainout | No Yes | No | Select to enable disable_chainout port. 
         Only available for the following operation modes: 
          
 | 
| Set the chainin and chainout width | chain_inout_width | 0 44 64 | 0 | Specify the width of chainin and chainout buses. 
         Only available for the following operation modes: 
          
 |