5.1.6 A_BLK_EN and B_BLK_EN

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A_BLK_EN is synchronized to A_CLK, while B_BLK_EN is synchronized to B_CLK. When two-port mode is in effect, the width of at least one port is greater than 20 bits, A_BLK_EN controls the read operation, and B_BLK_EN controls the write operation. The following table lists the block-port select control signals for the two ports.

Table 5-7. Block-Port Select
Block-Port Select Signal	Value	Result
A_BLK_EN[2:0]	111	Perform read or write operation on Port A. If the width is greater than 20 bits, a read is performed from both ports A and B.
A_BLK_EN[2:0]	Any one bit is 0	No operation in memory from Port A. Port A read data is forced to 0. If the width is greater than 20 bits, the read-data from both ports A and B is forced to 0.
B_BLK_EN[2:0]	111	Perform read or write operation on Port B, unless the width is greater than 20 bits and a write is performed to both ports A and B.
B_BLK_EN[2:0]	Any one bit is 0	No operation in memory from Port B. Port B read data is forced to 0, unless the width is greater than 20 bits and write operation to both ports A and B is gated.