RAM32X1S

32-Deep by 1-Wide Static Synchronous RAM

RAM32X1S is a 32-word by 1-bit static random access memory with synchronous write capability. When the write enable is Low, transitions on the write clock (WCLK) are ignored and data stored in the RAM is not affected. When WE is High, any positive transition on WCLK loads the data on the data input (D) into the word selected by the 5-bit address (A4 - A0). For predictable performance, address and data inputs must be stable before a Low-to-High WCLK transition. This RAM block assumes an active-High WCLK. However, WCLK can be active-High or active-Low. Any inverter placed on the WCLK input net is absorbed into the block.

The signal output on the data output pin (O) is the data that is stored in the RAM at the location defined by the values on the address pins.

Mode selection is shown in the following truth table.

Inputs			Outputs
WE (mode)	WCLK	D	O
0 (read)	X	X	Data
1 (read)	0	X	Data
1 (read)	1	X	Data
1 (write)		D	D
1 (read)		X	Data
Data = word addressed by bits A4 - A0

Specifying Initial Contents of a RAM32X1S

You can initialize RAM32X1S during configuration using the INIT attribute. The value must be a hexadecimal number, for example, INIT=ABAC. If the INIT attribute is not specified, the RAM is initialized with zero.

For XC4000E, XC4000X, Spartan, and SpartanXL, lower INIT values get mapped to the F function generator and upper INIT values get mapped to the G function generator.

For Virtex and Spartan2, lower INIT values get mapped to the G function generator and upper INIT values get mapped to the F function generator.