E2L0033-17-Y1
¡ Semiconductor
MSM518222
¡ Semiconductor
262,214-Word
¥
8-Bit Field Memory
This version: Jan. 1998
MSM518222
Previous version: Dec. 1996
DESCRIPTION
The OKI MSM518222 is a high performance 2-Mbit, 256K
¥
8-bit, Field Memory. It is designed for
high-speed serial access applications such as HDTVs, conventional NTSC TVs, VTRs, digital movies
and Multi-media systems. The 2-Mbit capacity fits one field of a conventional NTSC TV screen. Two
cascaded MSM518222s make one frame of the screen: two or more MSM518222s can be cascaded
directly without any delay devices between them. (Cascading provides larger storage depth or a
longer delay).
Each of the 8-bit planes has separate serial write and read ports. These employ independent control
clocks to support asynchronous read and write operations. Different clock rates are also supported,
which allow alternate data rates between write and read data streams.
The MSM518222 provides high speed FIFO, First-In First-Out, operation without external refreshing:
it refreshes its DRAM storage cells automatically, so that it appears fully static to the users.
Moreover, fully static type memory cells and decoders for serial access enable the refresh free serial
access operation, so that serial read and/or write control clock can be halted high or low for any
duration as long as the power is on. Internal conflicts of memory access and refreshing operations
are prevented by special arbitration logic.
The MSM518222's function is simple and similar to a digital delay device whose delay-bit-length is
easily set by reset timing. The delay length, and the number of read delay clocks between write and
read, is determined by externally controlled write and read reset timings.
Additional SRAM serial registers, or line buffers for the initial access of 256
¥
8-bit enable high speed
first-bit-access with no clock delay just after the write or read reset timings.
The MSM518222 is similar in operation and functionality to OKI 1-Mbit Field Memory MSM514221B,
with the addition of cascade capability. (As for MSM514221B operation compatible 2-Mbit Field
Memory, OKI has the MSM518221 which is a sister device of MSM518222).
Additionally, the MSM518222 has a write mask function or input enable function (IE), and read-data
skipping function or output enable function (OE). The differences between write enable (WE) and
input enable (IE), and between read enable (RE) and output enable (OE) are that WE and RE can stop
serial write/read address increments, but IE and OE cannot stop the increment, when write/read
clocking is continuously applied to MSM518222. The input enable (IE) function allows the user to
write into selected locations of the memory only, leaving the rest of the memory contents unchanged.
This facilitates data processing to display a "picture in picture" on a TV screen.
1/16
¡ Semiconductor
MSM518222
FEATURES
• Single power supply : 5 V
±10%
• 512 Rows
¥
512 Columns
¥
8 bits
• Fast FIFO (First-In First-Out) operation
• High speed asynchronous serial access
Read/write cycle time
25 ns/30 ns/40 ns
Access time
25 ns/25 ns/30 ns
• Direct cascading capability
• Write mask function (Input enable control)
• Data skipping function (Output enable control)
• Self refresh (No refresh control is required)
• Package options :
28-pin 400 mil plastic ZIP
(ZIP28-P-400-1.27)
28-pin 400 mil plastic SOJ
(SOJ28-P-400-1.27)
28-pin 430 mil plastic SOP
(SOP28-P-430-1.27-K)
(Product : MSM518222-xxZS)
(Product : MSM518222-xxJS)
(Product : MSM518222-xxGS-K)
xx indicates speed rank.
PRODUCT FAMILY
Family
MSM518222-25ZS
MSM518222-30ZS
MSM518222-40ZS
MSM518222-25JS
MSM518222-30JS
MSM518222-40JS
MSM518222-30GS-K
MSM518222-40GS-K
Access Time (Max.)
25 ns
25 ns
30 ns
25 ns
25 ns
30 ns
25 ns
30 ns
Cycle Time (Min.)
25 ns
30 ns
40 ns
25 ns
30 ns
40 ns
30 ns
40 ns
430 mil 28-pin SOP
400 mil 28-pin SOJ
400 mil 28-pin ZIP
Package
2/16
¡ Semiconductor
PIN CONFIGURATION (TOP VIEW)
WE
D
IN
0
D
IN
2
V
CC
D
IN
5
1
3
5
7
9
2
4
6
8
IE
D
IN
1
D
IN
3
D
IN
4
10 D
IN
6
12 RSTW
14 NC
16 RE
18 D
OUT
7
20 D
OUT
5
22 V
SS
24 D
OUT
2
26 D
OUT
0
28 SRCK
D
IN
7 11
SWCK 13
NC 15
OE 17
D
OUT
6 19
D
OUT
4 21
D
OUT
3 23
D
OUT
1 25
RSTR 27
D
IN
4 1
D
IN
5 2
D
IN
6 3
D
IN
7 4
28 V
CC
D
IN
4 1
D
IN
5 2
D
IN
6 3
D
IN
7 4
27 D
IN
3
26 D
IN
2
25 D
IN
1
24 D
IN
0
23 IE
22 WE
21 NC
RSTW 5
NC 7
RE 8
OE 9
RSTW 5
SWCK 6
SWCK 6
NC 7
RE 8
OE 9
20 SRCK
19 RSTR
18 D
OUT
0
17 D
OUT
1
16 D
OUT
2
15 D
OUT
3
D
OUT
7 10
D
OUT
6 11
D
OUT
5 12
D
OUT
4 13
V
SS
14
D
OUT
7 10
D
OUT
6 11
D
OUT
5 12
D
OUT
4 13
V
SS
14
28-Pin Plastic SOJ
MSM518222
28 V
CC
27 D
IN
3
26 D
IN
2
25 D
IN
1
24 D
IN
0
23 IE
22 WE
21 NC
20 SRCK
19 RSTR
18 D
OUT
0
17 D
OUT
1
16 D
OUT
2
15 D
OUT
3
28-Pin Plastic SOP
28-Pin Plastic ZIP
Pin Name
SWCK
SRCK
WE
RE
IE
OE
RSTW
RSTR
D
IN
0 - 7
D
OUT
0 - 7
V
CC
V
SS
NC
Function
Serial Write Clock
Serial Read Clock
Write Enable
Read Enable
Input Enable
Output Enable
Write Reset Clock
Read Reset Clock
Data Input
Data Output
Power Supply (5 V)
Ground (0 V)
No Connection
3/16
D
OUT
(¥ 8)
OE
RE
RSTR
SRCK
BLOCK DIAGRAM
Data-out
Buffer (¥ 8)
Serial
Controller
Read
¡ Semiconductor
512 Word Serial Read Register (¥ 8)
Read Line Buffer
Low-Half (¥ 8)
256 (¥ 8)
256 (¥ 8)
Read Line Buffer
High-Half (¥ 8)
71 Word
Sub-Register (¥ 8)
256K (¥ 8)
Memory
Array
Read/Write
and Refresh
Controller
X
Decoder
71 Word
Sub-Register (¥ 8)
256 (¥ 8)
256 (¥ 8)
Write Line Buffer
High-Half (¥ 8)
Write Line Buffer
Low-Half (¥ 8)
512 Word Serial Write Register (¥ 8)
V
BB
Generator
Clock
Oscillator
Data-in
Buffer (¥ 8)
Serial
Controller
Write
MSM518222
4/16
IE
WE
RSTW
D
IN
(¥ 8)
SWCK
¡ Semiconductor
MSM518222
OPERATION
Write Operation
The write operation is controlled by three clocks, SWCK, RSTW, and WE. Write operation is
accomplished by cycling SWCK, and holding WE high after the write address pointer reset operation
or RSTW.
Each write operation, which begins after RSTW, must contain at least 80 active write cycles, i.e.
SWCK cycles while WE is high. To transfer the last data to the DRAM array, which at that time
is stored in the serial data registers attached to the DRAM array, an RSTW operation is required
after the last SWCK cycle.
Note that every write timing of MSM518222 is delayed by one clock compared with read timings for
easy cascading without any interface delay devices.
Write Reset : RSTW
The first positive transition of SWCK after RSTW becomes high resets the write address counters to
zero. RSTW setup and hold times are referenced to the rising edge of SWCK. Because the write reset
function is solely controlled by the SWCK rising edge after the high level of RSTW, the states of WE
and IE are ignored in the write reset cycle.
Before RSTW may be brought high again for a further reset operation, it must be low for at least two
SWCK cycles.
Data Inputs : D
IN
0 - 7
Write Clock : SWCK
The SWCK latches the input data on chip when WE is high, and also increments the internal write
address pointer. Data-in setup time t
DS
, and hold time t
DH
are referenced to the rising edge of SWCK.
Write Enable : WE
WE is used for data write enable/disable control. WE high level enables the input, and WE low level
disables the input and holds the internal write address pointer. There are no WE disable time (low)
and WE enable time (high) restrictions, because the MSM518222 is in fully static operation as long
as the power is on. Note that WE setup and hold times are referenced to the rising edge of SWCK.
Input Enable : IE
IE is used to enable/disable writing into memory. IE high level enables writing. The internal write
address pointer is always incremented by cycling SWCK regardless of the IE level. Note that IE setup
and hold times are referenced to the rising edge of SWCK.
5/16
嵌入式系统
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
