6

M67206H

4143J–AERO–04/07

Functional Description

Single Device Mode

A single M67206H may be used when the application requirements are for 16384 words

or less. The M67206H is in a Single Device Configuration when the Expansion In (XI) control

input is grounded (see Figure 2). In this mode the Half-Full Flag (HF), which is an active low

output, is shared with Expansion Out (XO).

Figure 2. Block Diagram of Single 16384 bits × 9

Width Expansion Mode

Word width may be increased simply by connecting the corresponding input control sig-

nals of multiple devices. Status flags (EF, FF and HF) can be detected from any device.

Figure 3 demonstrates an 18-bit word width by using two M67206H. Any word width can be

attained by adding additional M67206H.

Figure 3. Block Diagram of 16384 bits x 18 FIFO Memory Used in Width Expansion Mode

Note:

Flag detection is accomplished by monitoring the FF, EF and the HF signals on either (any) device used in the width expansion

configuration. Do not connect any output control signals together.

(HALF-FULL FLAG)

WRITE

(W)

(R)

READ

DATAIN

9

(I)

DATAOUT

9

(Q)

FULL FLAG

RESET

(FF)

(RS)

EMPTY FLAG

RETRANSMIT

(EF)

(RT)

EXPANSION IN (XI)

HF

M67206H

HF

H