Cypress CY7C1146V18, CY7C1148V18, CY7C1150V18 manual Truth Table, SRAM#1 SRAM#2, Master, Operation

CY7C1146V18, CY7C1157V18 CY7C1148V18, CY7C1150V18

echo clock and follows the timing of any data pin. This signal is asserted half a cycle before valid data arrives.

DLL

These chips utilize a Delay Lock Loop (DLL) that is designed to function between 120 MHz and the specified maximum clock frequency. The DLL may be disabled by applying ground to the DOFF pin. When the DLL is turned off, the device behaves in

DDR-I mode (with 1.0 cycle latency and a longer access time). For more information, refer to the application note, “DLL Consid- erations in QDRII/DDRII/QDRII+/DDRII+”. The DLL can also be reset by slowing or stopping the input clocks K and K for a minimum of 30 ns. However, it is not necessary for the DLL to be reset in order to lock to the desired frequency. During Power up, when the DOFF is tied HIGH, the DLL gets locked after 2048 cycles of stable clock.

Application Example

Figure 1 shows two DDR-II+ used in an application.

Figure 1. Application Example

SRAM#1

ZQ

SRAM#2

ZQ

DQ

CQ/CQ

R = 250ohms

DQ

CQ/CQ

R = 250ohms

A

LD

R/W

K

K

A

LD

R/W

K

K

DQ

BUS

Addresses

MASTER

Cycle Start

(CPU or ASIC)

R/W

Source CLK

Source CLK

Echo Clock1/Echo Clock1

Echo Clock2/Echo Clock2

Truth Table

The truth table for the CY7C1146V18, CY7C1157V18, CY7C1148V18, and CY7C1150V18 follows. [3, 4, 5, 6, 7, 8]

Operation	K	LD	R/W	DQ	DQ
Write Cycle:	L – H	L	L	D(A) at K (t + 1) ↑	D(A + 1) at			(t + 1) ↑
						K
Load address; wait one cycle; input write data on consecutive
K and K rising edges.
Read Cycle: (2.0 cycle latency)	L – H	L	H	Q(A) at K (t + 2)↑	Q(A + 1) at			(t + 2) ↑
							K
Load address; wait two cycle; read data on consecutive K and
K rising edges.
NOP: No Operation	L – H	H	X	High-Z	High-Z
Standby: Clock Stopped	Stopped	X	X	Previous State	Previous State

Notes

2.The above application shows two DDR-II+ used.

3.X = “Don’t Care,” H = Logic HIGH, L = Logic LOW, ↑ represents rising edge.

4.Device powers up deselected and the outputs in a tri-state condition.

5.“A” represents address location latched by the devices when transaction was initiated and A + 1 represents the addresses sequence in the burst.

6.“t” represents the cycle at which a Read/Write operation is started. t + 1 and t + 2 are the first and second clock cycles succeeding the “t” clock cycle.

7.Data inputs are registered at K and K rising edges. Data outputs are delivered on K and K rising edges.

8.It is recommended that K = K = HIGH when clock is stopped. This is not essential, but permits most rapid restart by overcoming transmission line charging symmetrically.

Document Number: 001-06621 Rev. *D Page 9 of 27

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