Texas Instruments SM320C6455-EP manual BE1 BE2 BE3 BE4, EA1 EA2 EA3 EA4

						SM320C6455-EP
www.ti.com			FIXED-POINT DIGITAL SIGNAL PROCESSOR
				SPRS462B – SEPTEMBER 2007 – REVISED JANUARY 2008
		READ latency = 2
AECLKOUT
	1				1
ACEx
	2				3
ABE[7:0]	BE1	BE2	BE3	BE4
	4				5
AEA[19:0]/ABA[1:0]	EA1	EA2	EA3	EA4
			6	7
AED[63:0]			Q1	Q2	Q3	Q4
	8					8
ASADS/ASRE(B)
		9				9
AAOE/ASOE(B)

AAWE/ASWE(B)

A The following parameters are programmable via the EMIFA Chip Select n Configuration Register (CESECn):

−Read latency (R_LTNCY): 1-, 2-, or 3-cycle read latency −W rite latency (W_LTNCY): 0-, 1-, 2-, or 3-cycle write latency

−ACEx assertion length (CE_EXT): For standard SBSRAM or ZBT SRAM interface, ACEx goes inactive after the final command has been issued (CE_EXT = 0). For synchronous FIFO interface, ACEx is active when ASOE is active (CE_EXT = 1).

−Function of ASADS/ASRE (R_ENABLE): For standard SBSRAM or ZBT SRAM interface, ASADS/ASRE acts as ASADS with deselect cycles (R_ENABLE = 0). For FIFO interface, ASADS/ASRE acts as SRE with NO deselect cycles (R_ENABLE = 1).

−In this figure R_LTNCY = 2, CE_EXT = 0, R_ENABLE = 0, and SSEL = 1.

B AAOE/ASOE, and AAWE/ASWE operate as ASOE, and ASWE, respectively, during programmable synchronous interface accesses.

Figure 7-36. Programmable Synchronous Interface Read Timing for EMIFA (With Read Latency = 2)(A)

AECLKOUT
ACEx		1			1
		2			3
ABE[7:0]		BE1	BE2	BE3	BE4
		4			5
AEA[19:0]/ABA[1:0]		EA1	EA2	EA3	EA4
	10	10			11
AED[63:0]		Q1	Q2	Q3	Q4
ASADS/ASRE(B)		8			8
AAOE/ASOE(B)
		12			12
AAWE/ASWE(B)

AThe following parameters are programmable via the EMIFA Chip Select n Configuration Register (CESECn):

−Read latency (R_L TNCY): 1-, 2-, or 3-cycle read latency

−W rite latency (W_LTNCY): 0-, 1-, 2-, or 3-cycle write latency

−ACEx assertion length (CE_EXT): For standard SBSRAM or ZBT SRAM interface, ACEx goes inactive after the final command has been issued (CE_EXT = 0). For synchronous FIFO interface, ACEx is active when ASOE is active (CE_EXT = 1).

−Function of ASADS/ASRE (R_ENABLE): For standard SBSRAM or ZBT SRAM interface, ASADS/ASRE acts as ASADS with deselect cycles (R_ENABLE = 0). For FIFO interface, ASADS/ASRE acts as SRE with NO deselect cycles (R_ENABLE = 1).

−In this figure W_L TNCY = 0, CE_EXT = 0, R_ENABLE = 0, and SSEL = 1.

BAAOE/ASOE, and AAWE/ASWE operate as ASOE, and ASWE, respectively, during programmable synchronous interface accesses.

Figure 7-37. Programmable Synchronous Interface Write Timing for EMIFA (With Write Latency = 0)(A)

Submit Documentation Feedback C64x+ Peripheral Information and Electrical Specifications 169