Functional Description
Single Device Mode
A single M67204H may be used when the application requirements are for 4096 words
or less. The M67204H 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 out-
put, is shared with Expansion Out (XO).
Figure 2.
Block Diagram of Single 4096 bits x 9
(HALF-FULL FLAG)
)
WRITE
(W)
HF
9
DATA
IN
(I)
(Q)
9
DATA
OUT
(R)
READ
FULL FLAG
RESET
(FF)
(RS)
(EF) EMPTY FLAG
(RT) RETRANSMIT
EXPANSION IN (XI)
M67204H
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.
attained by adding additional M67204H.
Figure 3.
Block Diagram of 4096 bits
×
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.
6
M67204H
4141J–AERO–04/07
ATMEL [ ATMEL CORPORATION ]
