Parameters

INIT_FILE

String

No

Specifies the initialization file name. If the INIT_FILE parameter is specified, the INIT_TO_ZERO parameter value is overridden and initialization from internal ROM is performed. If the INIT_FILE and INIT_TO_ZERO parameter values are not specified, initialization from an external ROM address is performed; you must connect the appropriate ports when initialization is from an external ROM address.

INIT_TO_ZERO

String

No

Specifies whether the RAM must be initialized to contain all 0s. Values are "YES" and "NO". If omitted, the default is "NO". The INIT_FILE parameter value takes precedence over the INIT_TO_ZERO value setting.

NUMWORDS

Integer

Yes

Specifies the number of words stored in the ROM and the RAM memory.

WIDTHAD

Integer

Yes

Width of the ROM and the RAM.

WIDTH

Integer

Yes

Data width of the ROM and the RAM.

ROM_READ_LATENCY

Integer

No

Specifies the number of cycles to wait after the altmem_init megafunction sends a read address to the ROM to initialize a read. The value of the ROM_READ_LATENCY parameter must reflect the latency in clock cycles induced by the registers in the external ROM. For example, if the ROM has both its input

and output ports registered, set the ROM_READ_LATENCY parameter value to 2. This parameter is valid only in the external ROM mode.

PORT_ROM_DATA_READY

String

No

Specifies whether the rom_data_ready port is used. Values are "PORT_USED" and "PORT_UNUSED". If omitted, the default is "PORT_UNUSED". When the altmem_init megafunction is in external ROM mode, and the rom_data_ready input port is used, set the PORT_ROM_DATA_READY parameter value to "PORT_USED".