EMC646SP16J

4Mx16 CellularRAM

7

Preliminary

Table 1 : PIN Descriptions

Note:

1. When using asynchronous mode or page mode exclusively, CLK and ADV# inputs can be tied to Vss. WAIT will be asserted but should be ignored during asynchronous

and page mode operations.

Symbol

Type

Descriptions

A[21:0]

Input

Address inputs: Inputs for addresses during READ and WRITE operations. Addresses are internally latched

during READ and WRITE cycles. The address lines are also used to define the value to be loaded into the

BCR or the RCR.

CLK

(Note1)

Input

Clock: Synchronizes the memory to the system operating frequency during synchronous operations. When

configured for synchronous operation, the address is latched on the first rising CLK edge when ADV# is

active. CLK is static LOW during asynchronous access READ and WRITE operations and during PAGE

READ ACCESS operations.

ADV#

(Note1)

Input

Address valid: Indiates that a valid address is present on the address inputs. Addresses can be latched on

the rising edge of ADV# during asynchronous READ and WRITE operations. ADV# can be held LOW during

asynchronous READ and WRITE operations.

CRE

Input

Control register enable: When CRE is HIGH, WRITE operations load the RCR or BCR, and READ operations

access the RCR, BCR, or DIDR.

CE#

Input

Chip enable: Activates the device when LOW. When CE# is HIGH, the device is disabled and goes into

standby or deep power-down mode.

OE#

Input

Output enable: Enables the output buffers when LOW. When OE# is HIGH, the output buffers are disabled.

WE#

Input

Write enable: Determines if a given cycle is a WRITE cycle. If WE# is LOW, the cycle is a WRITE to either a

configuration register or to the memory array.

LB#

Input

Lower byte enable. DQ[7:0]

UB#

Input

Upper byte enable. DQ[15:8]

DQ[15:0]

Input/Output Data inputs/outputs.

WAIT

(Note1)

Output

Wait: Provides data-valid feedback during burst READ and WRITE operations. The signal is gated by CE#.

WAIT is used to arbitrate collisions between refresh and READ/WRITE operations. WAIT is also asserted at

the end of a row unless wrapping within the burst length. WAIT is asserted and should be ignored during

asynchronous and page mode operations. WAIT is High-Z when CE# is HIGH.

RFU

-

Reserved for future use.

Vcc

Supply

Device power supply: (1.70V.1.95V) Power supply for device core operation.

VccQ

Supply

I/O power supply: (1.70V.1.95V) Power supply for input/output buffers.

Vss

Supply

Vss must be connected to ground.

VssQ

Supply

VssQ must be connected to ground.