- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄39245 > LM12458MEL/883 (NATIONAL SEMICONDUCTOR CORP) PROPRIETARY METHOD ADC, PQCC44 PDF資料下載
參數(shù)資料
| 型號： | LM12458MEL/883 |
| 廠商： | NATIONAL SEMICONDUCTOR CORP |
| 元件分類： | ADC |
| 英文描述： | PROPRIETARY METHOD ADC, PQCC44 |
| 封裝： | EL44A |
| 文件頁數(shù)： | 24/43頁 |
| 文件大?。?/td> | 991K |
| 代理商： | LM12458MEL/883 |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁當前第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁第40頁第41頁第42頁第43頁
4.0 Sequencer
The Sequencer uses a 3-bit counter (Instruction Pointer, or
IP, in
Figure 9) to retrieve the programmable conversion in-
structions stored in the Instruction RAM. The 3-bit counter is
reset to 000 during chip reset or if the current executed in-
struction has its Loop bit (Bit 1 in any Instruction RAM “00”)
set high (“1”). It increments at the end of the currently ex-
ecuted instruction and points to the next instruction. It will
continue to increment up to 111 unless an instruction’s Loop
bit is set. If this bit is set, the counter resets to “000” and ex-
ecution begins again with the first instruction. If all instruc-
tions have their Loop bit reset to “0”, the Sequencer will ex-
ecute all eight instructions continuously. Therefore, it is
important to realize that if less than eight instructions are
programmed, the Loop bit on the last instruction must be set.
Leaving this bit reset to “0” allows the Sequencer to execute
“unprogrammed” instructions, the results of which may be
unpredictable.
The Sequencer’s Instruction Pointer value is readable at any
time and is found in the Status register at Bits 8–10. The Se-
quencer can go through eight states during instruction ex-
ecution:
State 0: The current instruction’s first 16 bits are read from
the Instruction RAM “00”. This state is one clock cycle long.
State 1: Checks the state of the Calibration and Start bits.
This is the “rest” state whenever the Sequencer is stopped
using the reset, a Pause command, or the Start bit is reset
low (“0”). When the Start bit is set to a “1”, this state is one
clock cycle long.
State 2: Perform calibration. If bit 2 or bit 6 of the Configu-
ration register is set to a “1”, state 2 is 76 clock cycles long.
If the Configuration register’s bit 3 is set to a “1”, state 2 is
4944 clock cycles long.
State 3: Run the internal 16-bit Timer. The number of
clock cycles for this state varies according to the value
stored in the Timer register. The number of clock cycles is
found by using the expression below
32T + 2
where 0
≤ T ≤ 216 1.
State 7: Run the acquisition delay and read Limit #1’s
value if needed. The number of clock cycles for 12-bit + sign
mode varies according to
9+2D
where D is the user-programmable 4-bit value stored in bits
12–15 of Instruction RAM “00” and is limited to 0
≤ D ≤ 15.
The number of clock cycles for 8-bit + sign or “watchdog”
mode varies according to
2+2D
where D is the user-programmable 4-bit value stored in bits
12–15 of Instruction RAM “00” and is limited to 0
≤ D ≤ 15.
State 6: Perform first comparison. This state is 5 clock
cycles long.
State 4: Read Limit #2. This state is 1 clock cycle long.
State 5: Perform a conversion or second comparison. This
state takes 44 clock cycles when using the 12-bit + sign
mode or 21 clock cycles when using the 8-bit + sign mode.
The “watchdog” mode takes 5 clock cycles.
www.national.com
30
相關PDF資料 |
PDF描述 |
|---|---|
| 5962-9319501MYA | SPECIALTY ANALOG CIRCUIT, PQCC44 |
| LM12H458MWG-MCP | SPECIALTY ANALOG CIRCUIT, CDFP44 |
| LM12H458MWG/883 | SPECIALTY ANALOG CIRCUIT, CDFP44 |
| LM1262NA/NOPB | 3 CHANNEL, VIDEO PREAMPLIFIER, PDIP24 |
| LM129BH/883 | 1-OUTPUT TWO TERM VOLTAGE REFERENCE, 6.9 V, MBCY2 |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| LM12458MW/883 | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Single-Ended Data Acquisition System |
| LM1246 | 制造商:NSC 制造商全稱:National Semiconductor 功能描述:150 MHz I2C Compatible RGB Preamplifier with Internal 512 Character OSD ROM, 512 Character RAM and 4 DACs |
| LM1246AAA | 制造商:NSC 制造商全稱:National Semiconductor 功能描述:150 MHz I2C Compatible RGB Preamplifier with Internal 512 Character OSD ROM, 512 Character RAM and 4 DACs |
| LM1246AAC/NA | 制造商:Rochester Electronics LLC 功能描述: 制造商:Texas Instruments 功能描述:IC 150MHZ RGB PREAMP 1246 DIP24 |
| LM1246AAC/NA/NOPB | 功能描述:IC PREAMP RGB 150MHZ 24-DIP RoHS:是 類別:集成電路 (IC) >> 線性 - 視頻處理 系列:- 產(chǎn)品變化通告:Product Discontinuation 07/Mar/2011 標準包裝:3,000 系列:OMNITUNE™ 類型:調(diào)諧器 應用:移動電話，手機，視頻顯示器 安裝類型:表面貼裝 封裝/外殼:65-WFBGA 供應商設備封裝:PG-WFSGA-65 包裝:帶卷 (TR) 其它名稱:SP000365064 |
發(fā)布緊急采購，3分鐘左右您將得到回復。