Megafunctions

altsyncram Megafunction



Parameterized true dual-port RAM megafunction. The altsyncram megafunction is available for Cyclone, Stratix, and Stratix GX devices only.

Altera® recommends instantiating this function as described in Using the MegaWizard® Plug-In Manager (Tools menu).

This topic contains the following information:


AHDL Function Prototype (port name and order also apply to Verilog HDL):

FUNCTION altsyncram (wren_a, wren_b, data_a[OPERATION_MODE != "ROM" ? WIDTH_A - 1 
      : 0..0], data_b[(OPERATION_MODE == "BIDIR_DUAL_PORT") ? WIDTH_B - 1 : 0..0], 
      address_a[WIDTHAD_A - 1..0], address_b[(OPERATION_MODE == "BIDIR_DUAL_PORT" 
      # OPERATION_MODE== "DUAL_PORT") ? WIDTHAD_B - 1 : 0..0], clock0, clock1, clocken0,
      clocken1, rden_b, aclr0, aclr1, byteena_a[OPERATION_MODE != "ROM" ? ((WIDTH_A 
      > 15) ? ((WIDTH_BYTEENA_A > 1 ? WIDTH_BYTEENA_A-1 : 0)) : 0 ): 0..0], 
      byteena_b[OPERATION_MODE == "BIDIR_DUAL_PORT" ? ((WIDTH_B > 15)?
      (WIDTH_BYTEENA_B > 1 ? WIDTH_BYTEENA_B-1 : 0) : 0 ): 0..0] )
   WITH ( OPERATION_MODE, WIDTH_A, WIDTHAD_A, NUMWORDS_A, INDATA_ACLR_A, WRCONTROL_ACLR_A,
      ADDRESS_ACLR_A, WIDTH_B, WIDTHAD_B, NUMWORDS_B, INDATA_REG_B, INDATA_ACLR_B, 
      WRCONTROL_WRADDRESS_REG_B, WRCONTROL_ACLR_B, ADDRESS_ACLR_B, OUTDATA_REG_A, 
      OUTDATA_ACLR_A, BYTEENA_ACLR_A, RDCONTROL_REG_B, RDCONTROL_ACLR_B, ADDRESS_REG_B,
      OUTDATA_REG_B, OUTDATA_ACLR_B, BYTEENA_REG_B, BYTEENA_ACLR_B, INIT_FILE, 
      INIT_FILE_LAYOUT, MAXIMUM_DEPTH, WIDTH_BYTEENA_A, WIDTH_BYTEENA_B, BYTE_SIZE,
      READ_DURING_WRITE_MODE_MIXED_PORTS, RAM_BLOCK_TYPE)
   RETURNS (q_a[WIDTH_A - 1..0], q_b[(OPERATION_MODE == "DUAL_PORT" # OPERATION_MODE 
      == "BIDIR_DUAL_PORT") ? WIDTH_B - 1 : 0..0] );


VHDL Component Declaration:

COMPONENT altsyncram 
   GENERIC 
      (OPERATION_MODE                    :  STRING  := "SINGLE_PORT";    -- "BIDIR_DUAL_PORT";
      WIDTH_A                            :  INTEGER := 8;    -- 1;
      WIDTHAD_A                          :  INTEGER := 2;    -- 1;
      NUMWORDS_A                         :  INTEGER := 4;    -- 1;
      OUTDATA_REG_A                      :  STRING  := "UNREGISTERED";
      ADDRESS_ACLR_A                     :  STRING  := "NONE";
      OUTDATA_ACLR_A                     :  STRING  := "NONE";
      INDATA_ACLR_A                      :  STRING  := "NONE";
      WRCONTROL_ACLR_A                   :  STRING  := "NONE";
      BYTEENA_ACLR_A                     :  STRING  := "NONE";
      WIDTH_BYTEENA_A                    :  INTEGER := 1;
      WIDTH_B                            :  INTEGER := 8;    -- 1;
      WIDTHAD_B                          :  INTEGER := 4;    -- 1;
      NUMWORDS_B                         :  INTEGER := 4;    -- 1;
      RDCONTROL_REG_B                    :  STRING  := "CLOCK1";
      ADDRESS_REG_B                      :  STRING  := "CLOCK1";
      INDATA_REG_B                       :  STRING  := "CLOCK1";
      WRCONTROL_WRADDRESS_REG_B          :  STRING  := "CLOCK1";
      BYTEENA_REG_B                      :  STRING  := "CLOCK1";
      OUTDATA_REG_B                      :  STRING  := "UNREGISTERED";
      OUTDATA_ACLR_B                     :  STRING  := "NONE";
      RDCONTROL_ACLR_B                   :  STRING  := "NONE";
      INDATA_ACLR_B                      :  STRING  := "NONE";
      WRCONTROL_ACLR_B                   :  STRING  := "NONE";
      ADDRESS_ACLR_B                     :  STRING  := "NONE";
      BYTEENA_ACLR_B                     :  STRING  := "NONE";
      WIDTH_BYTEENA_B                    :  INTEGER := 1;
      BYTE_SIZE                          :  INTEGER := 8;
      READ_DURING_WRITE_MODE_MIXED_PORTS :  STRING  := "DONT_CARE";    
      RAM_BLOCK_TYPE                     :  STRING  := "AUTO";    
      INIT_FILE                          :  STRING  := "UNUSED";    
      INIT_FILE_LAYOUT                   :  STRING  := "PORT_A";    
      MAXIMUM_DEPTH                      :  INTEGER := 0;    
      INTENDED_DEVICE_FAMILY             :  STRING  := "STRATIX";
      LPM_HINT                           :  STRING  := "BOGUS");

   PORT (wren_a, wren_b, aclr0, : IN STD_LOGIC := '0';   
           aclr1
        rden_b, clock0, clock1, : IN STD_LOGIC := '1';   
           clocken0, locken1
        data_a                  : IN STD_LOGIC_VECTOR(WIDTH_A - 1 DOWNTO 0):= (OTHERS => '0');
        data_b                  : IN STD_LOGIC_VECTOR(WIDTH_B - 1 DOWNTO 0):= (OTHERS => '0');
        address_a               : IN STD_LOGIC_VECTOR(WIDTHAD_A - 1 DOWNTO 0) := (OTHERS => '0');
        address_b               : IN STD_LOGIC_VECTOR(WIDTHAD_B - 1 DOWNTO 0) := (OTHERS => '0');
        byteena_a               : IN STD_LOGIC_VECTOR( (WIDTH_BYTEENA_A  - 1) DOWNTO 0) := (OTHERS => '1');
        byteena_b               : IN STD_LOGIC_VECTOR( (WIDTH_BYTEENA_B  - 1) DOWNTO 0) := (OTHERS => '1');
        q_a                     : OUT STD_LOGIC_VECTOR(WIDTH_A - 1 DOWNTO 0);
        q_b                     : OUT STD_LOGIC_VECTOR(WIDTH_B - 1 DOWNTO 0));

END COMPONENT; 

 

VHDL LIBRARY-USE Declaration

LIBRARY altera_mf;
USE altera_mf.altera_mf_components.all;


Port Descriptions:

INPUT PORTS

Port Name Required Description Comments
wren_a No Write enable input. The wren_a port is not available when the OPERATION_MODE parameter is set to "ROM" mode.
wren_b No Write enable input. The wren_b input port is available only when the OPERATION_MODE parameter is set to "BIDIR_DUAL_PORT".
rden_b No Read enable input port. The rden_b input port is available only when the OPERATION_MODE parameter is set to "DUAL_PORT" and when the RAM_BLOCK_TYPE parameter is not set to "MEGARAM".
data_a[] No Data input port to the memory. Input port WIDTH_A-1..0 wide.
data_b[] No Data input port to the memory. Input port WIDTH_B-1..0 wide.
address_a[] Yes Address input to the memory. Input port WIDTHAD_A-1..0 wide.
address_b[] Yes Address input to the memory. Input port WIDTHAD_B-1..0 wide.
clock0 Yes Clock input port for the RAM.  
clock1 No Clock input port for the RAM.  
clocken0 No Clock enable for clock0.  
clocken1 No Clock enable for clock1.  
aclr0 No The first asynchronous clear input.  
aclr1 No The second asynchronous clear input.  
byteena_a[] No Byte enable input port. Input port WIDTH_BYTEENA_A-1..0 wide. The byteena_a enable input port can be used only when the data_a port is at least two bytes wide.
byteena_b[] No Byte enable input port. Input port WIDTH_BYTEENA_B-1..0 wide. The byteena_b enable input port can be used only when the data_b port is at least two bytes wide.

OUTPUT PORTS

Port Name Required Description Comments
q_a[] Yes Data output port from the memory. Output port WIDTH_A-1..0 wide. The q_a[] port is legal only when the OPERATION_MODE parameter is set to "SINGLE_PORT", "BIDIR_DUAL_PORT", or "ROM".
q_b[] Yes Data output port from the memory. Output port WIDTH_B-1..0 wide. The q_b[] port is legal only when the OPERATION_MODE parameter is set to "DUAL_PORT" or "BIDIR_DUAL_PORT".


Parameter Descriptions:

Parameter Type Required Comments
OPERATION_MODE String Yes Specifies the operation of the RAM. Values are "SINGLE_PORT", "DUAL_PORT", "BIDIR_DUAL_PORT", or "ROM". If omitted, the default is "BIDIR_DUAL_PORT".
WIDTH_A Integer Yes Specifies the width of the data_a[] input port. If omitted, the default is "1".
WIDTHAD_A Integer Yes Specifies the width of the address_a[] input port. When the OPERATION_MODE parameter is set to "BIDIR_DUAL" mode, the WIDTH_A parameter is required. If omitted, the default is "1".
NUMWORDS_A Integer No Number of words stored in memory. If omitted, the default is 2 ^ WIDTHAD_A.
OUTDATA_REG_A String No Specifies the clock for the q_a[] port. Values are "CLOCK0", "CLOCK1", "UNREGISTERED", or "UNUSED". If omitted, the default is "UNREGISTERED".
ADDRESS_ACLR_A String No Specifies the asynchronous clear for the address_a[] port. Values are "CLEAR0", "NONE", or "UNUSED". If omitted, the default is "NONE".
OUTDATA_ACLR_A String No Specifies the asynchronous clear for the q_a[] output port. Values are "CLEAR0", "CLEAR1", "NONE", or "UNUSED". If omitted, the default is "NONE".
INDATA_ACLR_A String No Specifies the asynchronous clear for the data_a[]input port. Values are "CLEAR0", "NONE", or "UNUSED". If omitted, the default is "NONE".
WRCONTROL_ACLR_A String No Specifies the asynchronous clear for the wren_ainput port. Values are "CLEAR0", "NONE", or "UNUSED". If omitted, the default is "NONE".
BYTEENA_ACLR_A String No Specifies asynchronous clear for the byteena_a input port. Values are "CLEAR0", "CLEAR1", or "NONE". If omitted, the default is "NONE".
WIDTH_BYTEENA_A Integer No Specifies the width of the byteena_a input port. The WIDTH_BYTEENA_A parameter value must be equal to WIDTH_A / BYTE_SIZE. The WIDTH_BYTEENA_A parameter is required if the byteena_a port is specified.
WIDTH_B Integer No Specifies the width of the data_b[] input port. When the OPERATION_MODE parameter is set to "DUAL_PORT" mode, the WIDTH_B parameter is required. If omitted, the default is "1".
WIDTHAD_B Integer No Specifies the width of the address_b[] input port. If omitted, the default is "1".
NUMWORDS_B Integer No Number of words stored in memory. If omitted, the default is 2 ^ WIDTHAD_B.
RDCONTROL_REG_B String No Specifies the clock for the rden_b port during read mode. Values are "CLOCK0", "CLOCK1", or "UNUSED". If omitted, the default is "CLOCK1".
ADDRESS_REG_B String No Specifies the clock for the address_b[] port. Values are "CLOCK0", "CLOCK1", or "UNUSED". If omitted, the default is "CLOCK1".
INDATA_REG_B String No Specifies the clock for the data_b[] port. Values are "CLOCK0", "CLOCK1", or "UNUSED". If omitted, the default is "CLOCK1".
WRCONTROL_WRADDRESS_REG_B String No Specifies the clock for the wren_b and address_b[] port during write mode. Values are "CLOCK0", "CLOCK1", or "UNUSED". If omitted, the default is "CLOCK1".
BYTEENA_REG_B String No Specifies the clock for the byteena_b[] port. Values are "CLOCK0", "CLOCK1", or "UNUSED". If omitted, the default is "CLOCK1".
OUTDATA_REG_B String No Specifies the clock for the q_b[] port. Values are "CLOCK0", "CLOCK1", "UNREGISTERED", or "UNUSED". If omitted, the default is "UNREGISTERED".
OUTDATA_ACLR_B String No Specifies the asynchronous clear for the q_b[] output port. Values are "CLEAR0", "CLEAR1", "NONE", or "UNUSED". If omitted, the default is "NONE".
RDCONTROL_ACLR_B String No Specifies the clear source for the port B read enable control register. Values are "CLEAR0", "CLEAR1", "NONE", or "UNUSED". The default value is "NONE".
INDATA_ACLR_B String No Specifies the asynchronous clear for the data_b[]input port. Values are "CLEAR0", "NONE", or "UNUSED". If omitted, the default is "NONE".
WRCONTROL_ACLR_B String No Specifies the asynchronous clear for the wren_binput port. Values are "CLEAR0", "NONE", or "UNUSED". If omitted, the default is "NONE".
ADDRESS_ACLR_B String No Specifies the asynchronous clear for the address_b[] port. Values are "CLEAR0", "NONE", or "UNUSED". If omitted, the default is "NONE".
BYTEENA_ACLR_B String No Specifies asynchronous clear for the byteena_b input port. Values are "CLEAR0", "CLEAR1", "NONE", or "UNUSED". If omitted, the default is "NONE".
WIDTH_BYTEENA_B Integer No Specifies the width of the byteena_b input port. The WIDTH_BYTEENA_B parameter value must be equal to WIDTH_B / BYTE_SIZE. The WIDTH_BYTEENA_B parameter is required if the byteena_b port is specified.
BYTE_SIZE Integer No Specifies the byte enable size. Values are "8" or "9". If omitted, the default is "8".
READ_DURING_WRITE_MODE_MIXED_PORTS String No Specifies the behavior when the read and write operations occur at different ports on the same RAM address. Values are "OLD_DATA" or "DONT_CARE". The default value is "DONT_CARE". When the OPERATION_MODE parameter is set to "MEGARAM", the READ_DURING_WRITE_MODE_MIXED_PORTS parameter must be set to "DONT_CARE".
RAM_BLOCK_TYPE String No Specifies the RAM block type. Values are "M512", "M4K", "MEGARAM", or "AUTO". If omitted, the default is "AUTO".
INIT_FILE String No Name of the Memory Initialization File (.mif) or Hexadecimal (Intel-Format) Output File (.hexout) containing RAM initialization data ("<file name>"), or "UNUSED". The default is "UNUSED". The INIT_FILE parameter is unavailable when the RAM_BLOCK_TYPE parameter is set to MEGARAM. When the OPERATION_MODE parameter is set to "DUAL_PORT", the Compiler uses only the WIDTH_B parameters to read the initialization file.
INIT_FILE_LAYOUT String No Specifies the layout port used with the initialization file. Values are "PORT_A" or "PORT_B". If the OPERATION_MODE is set to "DUAL_PORT" mode, the default value is "PORT_B". If the OPERATION_MODE is set to other modes, the the default value is "PORT_A".
MAXIMUM_DEPTH Integer No Specifies the maximum segmented value of the RAM. The MAXIMUM_DEPTH parameter value depends on the RAM_BLOCK_TYPE parameter. If omitted, the default is "0".
INTENDED_DEVICE_FAMILY String No This parameter is used for modeling and behavioral simulation purposes. Create the PLL with the MegaWizard Plug-in Manager to calculate the value for this parameter.
LPM_HINT String No Allows you to assign Altera-specific parameters in VHDL Design Files (.vhd). If omitted, the default is "UNUSED".


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