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参数资料
| 型号： | MSM518221A |
| 厂商： | OKI SEMICONDUCTOR CO., LTD. |
| 英文描述： | 262,214-Word x 8-Bit Field Memory |
| 中文描述： | 262214字× 8位字段记忆 |
| 文件页数： | 7/17页 |
| 文件大小： | 200K |
| 代理商： | MSM518221A |
Semiconductor
MSM518221A
7/16
Power-up and Initialization
On power-up, the device is designed to begin proper operation after at least 100
m
s after V
CC
has
stabilized to a value within the range of recommended operating conditions. After this 100
m
s
stabilization interval, the following initialization sequence must be performed.
Because the read and write address counters are not valid after power-up, a minimum of 80 dummy
write operations (SWCK cycles) and read operations (SRCK cycles) must be performed, followed by
an RSTW operation and an RSTR operation, to properly initialize the write and the read address
pointer. Dummy write cycles/RSTW and dummy read cycles/RSTR may occur simultaneously.
If these dummy read and write operations start while V
CC
and/or the substrate voltage has not
stabilized, it is necessary to perform an RSTR operation plus a minimum of 80 SRCK cycles plus
another RSTR operation, and an RSTW operation plus a minimum of 80 SRCK cycles plus another
RSTW operation to properly initialize read and write address pointers.
Old/New Data Access
There must be a minimum delay of 600 SWCK cycles between writing into memory and reading out
from memory. If reading from the first field starts with an RSTR operation, before the start of writing
the second field (before the next RSTW operation), then the data just written will be read out.
The start of reading out the first field of data may be delayed past the beginning of writing in the
second field of data for as many as 70 SWCK cycles. If the RSTR operation for the first field read-out
occurs less than 70 SWCK cycles after the RSTW operation for the second field write-in, then the
internal buffering of the device assures that the first field will still be read out. The first field of data
that is read out while the second field of data is written is called "old data".
In order to read out "new data", i.e., the second field written in, the delay between an RSTW
operation and an RSTR operation must be at least 600 SRCK cycles. If the delay between RSTW and
RSTR operations is more than 71 but less than 600 cycles, then the data read out will be undetermined.
It may be "old data" or "new" data, or a combination of old and new data. Such a timing should be
avoided.
相关PDF资料 |
PDF描述 |
|---|---|
| MSM518221A-25JS | 262,214-Word x 8-Bit Field Memory |
| MSM518221A-25ZS | 262,214-Word x 8-Bit Field Memory |
| MSM518221A-30GS-K | 262,214-Word x 8-Bit Field Memory |
| MSM518221A-30JS | 262,214-Word x 8-Bit Field Memory |
| MSM518221A-30ZS | 262,214-Word x 8-Bit Field Memory |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MSM518221A-25J3 | 制造商:ROHM Semiconductor 功能描述: |
| MSM518221A-25JS | 制造商:OKI 制造商全称:OKI electronic componets 功能描述:262,214-Word x 8-Bit Field Memory |
| MSM518221A-25Z3 | 制造商:ROHM Semiconductor 功能描述: |
| MSM518221A-25ZS | 制造商:OKI 制造商全称:OKI electronic componets 功能描述:262,214-Word x 8-Bit Field Memory |
| MSM518221A-30GS-K | 制造商:OKI 制造商全称:OKI electronic componets 功能描述:262,214-Word x 8-Bit Field Memory |
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