- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄379503 > UPD7554AA (NEC Corp.) 4-BIT SINGLE-CHIP MICROCOMPUTER PDF資料下載
參數(shù)資料
| 型號(hào)： | UPD7554AA |
| 廠商： | NEC Corp. |
| 英文描述： | 4-BIT SINGLE-CHIP MICROCOMPUTER |
| 中文描述： | 4位單片機(jī) |
| 文件頁數(shù)： | 20/64頁 |
| 文件大?。?/td> | 991K |
| 代理商： | UPD7554AA |
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頁當(dāng)前第20頁第21頁第22頁第23頁第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頁第44頁第45頁第46頁第47頁第48頁第49頁第50頁第51頁第52頁第53頁第54頁第55頁第56頁第57頁第58頁第59頁第60頁第61頁第62頁第63頁第64頁
20
μ
PD7554A, 7554A(A)
2.9
SYSTEM CLOCK GENERATOR
The system clock generator contains an RC oscillator, 1/2 divider, and standby (STOP/HALT) mode control circuit.
Fig. 2-9 System Clock Generator
STANDBY RELEASE
RESET ( )
(To CPU)
φ
CL (System Clock)
RESET (High)
HALT
Note
STOP
Note
HALT F/F
Q
S
R
Q
S
R
STOP F/F
CL2
CL1
C
R
1/2
RC
Oscillator
Note
Instruction execution
Oscillator
Stop
The RC oscillator oscillates with an external resistor R connected to pins CL1 and CL2. (A capacitor C is
incorporated.)
The RC oscillator serves merely as a reverse buffer if inputs an external clock through the CL1 input.
The RC oscillator outputs the system clock (CL) which is 1/2 divided to the CPU clock (
φ
).
The control circuit in the standby mode consists mainly of STOP F/F and HALT F/F.
The STOP F/F is set by the STOP instruction, blocking any clock from being supplied. The STOP F/F stops RC
oscillation during operation of the RC oscillator (STOP mode).
The STOP F/F is reset by the STANDBY RELEASE signal (which goes active when even one test request flag is
input) or at the fall of the RESET input, to cause the RC oscillator to start oscillation and supplying each clock.
The HALT F/F is set by the HALT instruction to disable the input to the 1/2 divider which generates the CPU clock
φ
, stopping only the CPU clock
φ
(HALT mode).
The HALT F/F is set and reset as in the case of the STOP F/F. Resetting the HALT F/F cause the RC oscillator to
start supplying the CPU clock
φ
.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| UPD7554ACS | 4-BIT SINGLE-CHIP MICROCOMPUTER |
| UPD7554AG | 4-BIT SINGLE-CHIP MICROCOMPUTER |
| UPD75CG08E | 4 BIT SINGLE CHIP CMOS MICROCOMPUTERS |
| UPD7508 | 4 BIT SINGLE CHIP CMOS MICROCOMPUTERS |
| UPD7508C | 4 BIT SINGLE CHIP CMOS MICROCOMPUTERS |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| UPD7554AG-597-E2 | 制造商:Renesas Electronics Corporation 功能描述: |
| UPD7554AG-597-E2-A | 制造商:Renesas Electronics Corporation 功能描述: |
| UPD7554AG-603-E2 | 制造商:Renesas Electronics Corporation 功能描述: |
| UPD7554AG-603-E2-A | 制造商:Renesas Electronics Corporation 功能描述: |
| UPD7554AG-611-E2 | 制造商:Renesas Electronics Corporation 功能描述: |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。