Dsp48E1 Slice Attributes - Xilinx 7 Series User Manual

Chapter 2: DSP48E1 Description and Specifics

DSP48E1 Slice Attributes

The synthesis attributes for the DSP48E1 slice are described in this section. The attributes
call out pipeline registers in the control and datapaths. The value of the attribute sets the
number of pipeline registers. See
Table 2-3: Attribute Setting Description
Attribute Name
Register Control Attributes
ACASCREG
ADREG
ALUMODEREG
AREG
BCASCREG
BREG
CARRYINREG
CARRYINSELREG
CREG
DREG
INMODEREG
MREG
OPMODEREG
PREG
Feature Control Attributes
A_INPUT
B_INPUT
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0, 1, 2 (1) In conjunction with AREG, selects the number of A input
registers on the A cascade path, ACOUT. This attribute must be
equal to or one less than the AREG value:
0, 1 (1) Selects the number of AD pipeline registers.
0, 1 (1) Selects the number of ALUMODE input registers.
0, 1, 2 (1) Selects the number of A input registers. When 1 is selected, the
A2 register is used.
0, 1, 2 (1) In conjunction with BREG, selects the number of B input
registers on the B cascade path, BCOUT. This attribute must be
equal to or one less than the BREG value:
0, 1, 2 (1) Selects the number of B input registers. When 1 is selected, the
B2 register is used.
0, 1 (1) Selects the number of fabric CARRYIN input registers.
0, 1 (1) Selects the number of CARRYINSEL input registers.
0, 1 (1) Selects the number of C input registers.
0, 1 (1) Selects the number of D input registers.
0, 1 (1) Selects the number of INMODE input registers.
0, 1 (1) Selects the number of M pipeline registers.
0, 1 (1) Selects the number of OPMODE input registers.
0, 1 (1) Selects the number of P output registers (also used by
CARRYOUT/ PATTERN_DETECT/ CARRYCASCOUT/
MULTSIGNOUT, etc.).
DIRECT, CASCADE Selects the input to the A port between parallel input (DIRECT)
(DIRECT) or the cascaded input from the previous slice (CASCADE).
DIRECT, CASCADE Selects the input to the B port between parallel input (DIRECT)
(DIRECT) or the cascaded input from the previous slice (CASCADE).
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Table 2-3.
Attribute Description
AREG = 0: ACASCREG must be 0
AREG = 1: ACASCREG must be 1
AREG = 2: ACASCREG can be 1 or 2
BREG = 0: BCASCREG must be 0
BREG = 1: BCASCREG must be 1
BREG = 2: BCASCREG can be 1 or 2
7 Series DSP48E1 User Guide
UG479 (v1.10) March 27, 2018