Latency Values of Floating-Point Operators

HDL Coder™ native floating-point support can generate HDL code from your floating-point design. HDL Coder supports several Simulink^® blocks, Math and Trigonometric Functions blocks in native floating-point mode. The tables list the default latency values of these floating-point operations.

You can customize the latency settings for the blocks and design for trade-offs between latency and maximum frequency. For more information, see NFPCustomLatency.

You can also set the global custom latency of native floating-point IPs. Use the keywords listed in the tables to specify the global custom latency of the floating-point IPs. For more information on setting the custom latency of floating-point IPs, see Latency Considerations with Native Floating Point.

You can see the latency of these floating-point operators in MATLAB^® by entering these commands.

nfpconfig = hdlcoder.createFloatingPointTargetConfig('NativeFloatingPoint');
nfpconfig.IPConfig

Math Operations

This table shows the list of basic math operations that are supported with native floating-point in HDL Coder and their latency information. The basic math operations include addition, subtraction, multiplication, and so on. You can use most of these blocks with both single and double data types. If you do not see an entry of double data type corresponding to a block, it means that the block does not support double types.

Basic Math Operators

Simulink Blocks	Keywords	Data Type	Minimum Output Latency	Maximum Output Latency	Custom Latency Support
Sum	`ADDSUB`	Double	6	11	Yes
		Single	6	11
		Half	4	8
Product, Matrix Multiply or Gain	`MUL`	Double	6	9	Yes
		Single	6	8
		Half	4	7
Divide	`DIV`	Double	31	61	Yes
		Single	17	32
		Half	10	19
Product, Matrix Multiply Reciprocal	`RECIP`	Double	30	60	Yes
		Single	16	31
		Half	10	19
Multiply-Add	`MULTADD`	Single	8	14	No
Sqrt	`SQRT`	Double	33	58	Yes
		Single	16	28
		Half	6	12
HDL Reciprocal	`HDLRECIP`	Single	14	21	No
Rounding Function	`ROUNDING`	Double	3	5	Yes
Rounding Function	`ROUNDING`	Single	3	5	Yes
Gain(Power of 2)	`GAINPOW2`	Double	1	2	Yes
		Single	1	2
		Half	1	4

This table shows the math functions that are supported with native floating-point in HDL Coder and their latency information. You can select the function using the Function setting of the Math Function block.

Math Functions

Simulink Blocks	Keywords	Data Type	Minimum Output Latency	Maximum Output Latency	Custom Latency Support
Rem	`REM`	Single	15	24	No
Mod	`MOD`	Single	16	26	No
Reciprocal Sqrt	`RSQRT`	Single	16	30	Yes
Hypot	`HYPOT`	Single	17	33	No
Reciprocal	`RECIP`	Double	30	60	Yes
		Single	16	31
		Half	10	19
Magnitude Square	-	Double	6	9	Yes
Magnitude Square	-	Single	6	8	Yes

This table shows the exponential operations that are supported with native floating-point in HDL Coder and their latency information. You can select the function using the Function setting of the Math Function block. You can use these blocks with single data types. Double types are unsupported for the blocks except Log.

Exponent/Logarithm/Power

Simulink Blocks	Keywords	Data Type	Minimum Output Latency	Maximum Output Latency	Custom Latency Support
Exp	`EXP`	Single	16	26	No
Pow	`POW`	Single	33	54	No
Pow10	`POW10`	Single	16	26	No
Log	`LOG`	Double	34	44	No
		Single	20	27
		Half	9	17
Log10	`LOG10`	Single	17	27	No
Log10	`LOG10`	Half	10	18	No

Trigonometric Operations

This table shows the trigonometric operations that are supported with native floating-point in HDL Coder and their latency information. You can select the function using the Function setting of the Trigonometric Function block. You can use these blocks with single data types.

Trigonometric Functions

Simulink Blocks	Keywords	Data Type	Minimum Output Latency	Maximum Output Latency	Custom Latency Support
Sin	`SIN`	Double	34	34	No
		Single	27	27
		Half	8	14
Cos	`COS`	Double	48	48	No
		Single	27	27
		Half	9	14
Tan	`TAN`	Single	33	33	No
Sincos	`SINCOS`	Single	27	27	No
Asin	`ASIN`	Single	17	23	No
Acos	`ACOS`	Single	17	23	No
Atan	`ATAN`	Single	36	36	No
Atan2	`ATAN2`	Single	42	42	No
Sinh	`SINH`	Single	18	30	No
Cosh	`COSH`	Single	17	27	No
Tanh	`TANH`	Single	25	43	No
Asinh	`ASINH`	Single	94	94	No
Acosh	`ACOSH`	Single	93	93	No
Atanh	`ATANH`	Single	67	67	No

Comparisons and Conversions

This table shows operations related to relational operators and data type conversions that are supported with native floating-point in HDL Coder and their latency information. You can use these blocks with both single and double data types except for the MinMax block. This block does not support double data type. For the Data Type Conversion block, you can convert between double, half, and single data types, and between floating-point and other fixed-point data types.

Comparisons and Conversions

Simulink Blocks	Keywords	Data Type	Minimum Output Latency	Maximum Output Latency	Custom Latency Support
Data Type Conversion	`CONVERT`	DOUBLE_TO_NUMERICTYPE	3	6	Yes
		DOUBLE_TO_SINGLE	3	6
		HALF_TO_NUMERICTYPE	2	3
		HALF_TO_SINGLE	1	2
		NUMERICTYPE_TO_DOUBLE	3	6
		NUMERICTYPE_TO_HALF	2	4
		NUMERICTYPE_TO_SINGLE	6	6
		SINGLE_TO_DOUBLE	3	5
		SINGLE_TO_HALF	2	3
		SINGLE_TO_NUMERICTYPE	6	6
Relational Operator	`RELOP`	Double	1	3	Yes
		Single	1	3
		Half	1	2
MinMax	`MINMAX`	Single	3	3	No

Related Examples

Floating Point Support: Field-Oriented Control Algorithm