¡ Semiconductor
MSM6791
MSM6791
DRAM Interface IC
¡ Semiconductor
GENERAL DESCRIPTION
The MSM6791 can be used as a memory for voice data by connecting OKI solid-state recording
and playback ICs (MSM6688 and MSM6788).
FEATURES
• DRAM (¥ 1-bit configuration)
1M-bit DRAM (MSM511000A, MSM511001A) : 8 pcs. can be connected.
4M-bit DRAM (MSM514100A, MSM514101A) : 8 pcs. can be connected.
16M-bit DRAM (MSM5116100A)
: 2 pcs. can be connected.
Note:
MSM511002A/MSM514102A that corresponds to a static column mode cannot be used.
5V single rail
8MHz
10kbps, 12.5kbps, 16kbps in MSM6788
connection (8kHz sampling fixation)
7.5kbps, 9.4kbps, 12kbps in MSM6788
connection (6kHz sampling fixation)
16kbps~32kbps in MSM6688 connection
(4kHz~8kHz sampling)
• Power supply voltage :
• Built-in refresh circuit (RAS only refresh)
• Original oscillation frequency:
• Bit rates:
• Package:
44-pin plastic QFP (QFP44-P-910-2K) (Product name : MSM6791GS-2K)
¡ Semiconductor
MSM6791
BLOCK DIAGRAM
TEST
TEST
GND
GND
V
DD
V
DD
SAD
Sin
Pout
13
13
Column
or Row
Address
Multi-
plexer
Row.A11
10
TAS
Address
Multi-
plexer
12
A0
A1
A2
A3
A4
A5
A6
A7
R
Column
Address
Counter
Rerfresh
Counter
12
A8
A9
A10
A11
CK
SAS
Column
and Row
Address
Counter
LD
CK
3
XT
XT
OSC
WE
RWCK
CS1
CS2
CS3
CS4
Timing
Controller
DRAM
Controller
CAS
Controller
CAS1
CAS2
CAS3
CAS4
CAS5
CAS6
CAS7
M1
M2
CAS8
XWE
RAS
DOUT
XDIN
MSM6791
¡ Semiconductor
PIN CONFIGURATION (TOP VIEW)
A11
A10
V
DD
A6
A5
A4
36
A3
35
A9
A8
A7
A2
34
44
43
42
41
40
39
38
RWCK
DOUT
WE
SAD
SAS
GND
TEST
TAS
CS1
CS2
NC
37
1
2
3
4
5
6
7
8
9
10
11
33
32
31
30
29
28
27
26
25
24
23
A1
A0
RAS
XDIN
XWE
GND
XT
XT
CAS8
CAS7
CAS6
12
13
14
15
16
17
18
19
20
CAS3
21
CAS4
CS3
CS4
M1
M2
TEST
CAS1
CAS2
44-Pin Plastic QFP
NC: No-connection pin
CAS5
V
DD
22
¡ Semiconductor
MSM6791
PIN DESCRIPTION
Symbol
V
DD
GND
XT
XT
TEST
TEST
SAD
SAS
TAS
Type
–
–
I
O
I
I
I
I
I
Power supply
Ground
Oscillator
Oscillator
IC test. Use this pin by setting to ‘L’ level.
IC test. Use this pin by setting to ‘H’ level.
Read/write head address
Clock to take the serial address data in the internal register
Serial address data taken in the address register to the internal address counter
Clock to read and write the information of the data register. The internal operation starts by the
fall edge of
RWCK.
In a read mode, the data taken in XDIN is latched and it is output to the
RWCK
I
DOUT pin. In a write mode, the DI/O output data of MSM6688/6788/6789 is taken in the DIN
pin of the DRAM. In addition, the internal address counter automatically increments by the fall
edge of
RWCK
and the address data output from A0 to A11.
WE
XWE
A0~A11
RAS
CAS1
~
O
I
O
DRAM control
Data input
Data output
Chip select data in connecting DRAM
By inputting a "L" level signal to each pin, up to 32M-bit of memory (8M-bit of memory for
I
each pin) can be controlled for four Pins.
These pins become the input pins to select the highest address in 16M-bit DRAM connection.
Set the connecting pattern of DRAM.
M1
I
M2
Connecting
Mode
Mode 0
Mode 1
Mode 2
Mode 3
M2
L
L
H
H
M1
L
H
L
H
DRAM Connecting Pattern
1M-bit DRAM
¥
1~8pcs. connectable
4M-bit DRAM
¥
1~8pcs. connectable
(4M-bit DRAM
¥
1pcs.) + (1M-bit DRAM
¥
0~3pcs.) connectable
16M-bit DRAM
¥
1~2pcs. connectable
CAS8
XDIN
DOUT
CS1
CS2
CS3
CS4
I
O
O
O
Select a read mode and write mode.
DRAM control
DRAM address
DRAM control
Description
MSM6791
¡ Semiconductor
ABSOLUTE MAXIMUM RATINGS
Parameter
Supply Voltage
Input Voltage
Output Voltage
Input Current
Output Current
Storage Temperature
Symbol
V
DD
V
I
V
O
I
I
I
O
T
STG
—
GND = 0V
Ta = 25˚C
Condition
Rating
–0.5 to +7
–0.5 to V
DD
+0.5
–0.5 to V
DD
+0.5
–10 to +10
–20 to +20
–65 to +150
Unit
V
V
V
mA
mA
˚C
RECOMMENDED OPERATING CONDITIONS
GND = 0V
Parameter
Supply Voltage
Operating Temperature
Oscillation Frequency
Symbol
V
DD
T
OP
f
OSC
Range
4.5 to 5.5
–40 to +85
8
Unit
V
˚C
MHz
ELECTRICAL CHARACTERISTICS
DC Characteristics
(Ta = –40 to +85˚C, VDD = 5V±10% GND = 0V)
Parameter
"H" Level Input Voltage
"L" Level Input Voltage
"H" Level Input Current
"L" Level Input Current
3-state Output Leak Current
(includes open-drain output)
H" Level Output Voltage
"L" Level Output Voltage
Operational
Current Consumption
Symbol
V
IH
V
IL
I
IH
I
IL
I
OZH
I
OZL
V
OH
V
OL
I
DD
Condition
—
—
V
IH
= V
DD
V
IL
= GND
V
OH
= V
DD
V
OL
= GND
I
OH
= –5.0 mA
I
OL
= 5.0 mA
Output open f
OSC
= 8MHz
V
IH
= V
DD
V
IL
= GND
—
—
3
mA
Min.
3.5
–0.3
—
–10
—
–10
2.4
V
SS
Typ.
*1
—
—
0.01
–0.01
0.01
–0.01
4.20
0.24
Max.
V
DD
+0.3
1.5
10
—
10
—
V
DD
0.5
Unit
V
V
mA
mA
mA
mA
V
V
*1 TYP means V
DD
=5.0V, Ta=25°C
电源技术