- 您現在的位置：買賣IC網 > PDF目錄24814 > 935265431112 (NXP SEMICONDUCTORS) 8-BIT, FLASH, 33 MHz, MICROCONTROLLER, PDIP40 PDF資料下載
參數資料
| 型號： | 935265431112 |
| 廠商： | NXP SEMICONDUCTORS |
| 元件分類： | 微控制器/微處理器 |
| 英文描述： | 8-BIT, FLASH, 33 MHz, MICROCONTROLLER, PDIP40 |
| 封裝： | PLASTIC, DIP-40 |
| 文件頁數： | 2/52頁 |
| 文件大小： | 288K |
| 代理商： | 935265431112 |
第1頁當前第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
Philips Semiconductors
Preliminary data
P89C51RB2/P89C51RC2/
P89C51RD2
80C51 8-bit Flash microcontroller family
16KB/32KB/64KB ISP/IAP Flash with 512B/512B/1KB RAM
2001 Jun 27
10
LOW POWER MODES
Stop Clock Mode
The static design enables the clock speed to be reduced down to
0 MHz (stopped). When the oscillator is stopped, the RAM and
Special Function Registers retain their values. This mode allows
step-by-step utilization and permits reduced system power
consumption by lowering the clock frequency down to any value. For
lowest power consumption the Power Down mode is suggested.
Idle Mode
In the idle mode (see Table 2), the CPU puts itself to sleep while all
of the on-chip peripherals stay active. The instruction to invoke the
idle mode is the last instruction executed in the normal operating
mode before the idle mode is activated. The CPU contents, the
on-chip RAM, and all of the special function registers remain intact
during this mode. The idle mode can be terminated either by any
enabled interrupt (at which time the process is picked up at the
interrupt service routine and continued), or by a hardware reset
which starts the processor in the same manner as a power-on reset.
Power-Down Mode
To save even more power, a Power Down mode (see Table 2) can
be invoked by software. In this mode, the oscillator is stopped and
the instruction that invoked Power Down is the last instruction
executed. The on-chip RAM and Special Function Registers retain
their values down to 2.0 V and care must be taken to return VCC to
the minimum specified operating voltages before the Power Down
Mode is terminated.
Either a hardware reset or external interrupt can be used to exit from
Power Down. Reset redefines all the SFRs but does not change the
on-chip RAM. An external interrupt allows both the SFRs and the
on-chip RAM to retain their values.
To properly terminate Power Down, the reset or external interrupt
should not be executed before VCC is restored to its normal
operating level and must be held active long enough for the
oscillator to restart and stabilize (normally less than 10 ms).
With an external interrupt, INT0 and INT1 must be enabled and
configured as level-sensitive. Holding the pin low restarts the oscillator
but bringing the pin back high completes the exit. Once the interrupt
is serviced, the next instruction to be executed after RETI will be the
one following the instruction that put the device into Power Down.
POWER OFF FLAG
The Power Off Flag (POF) is set by on-chip circuitry when the VCC
level on the P89C51RB2/RC2/RD2 rises from 0 to 5 V. The POF bit
can be set or cleared by software allowing a user to determine if the
reset is the result of a power-on or a warm start after powerdown.
The VCC level must remain above 3 V for the POF to remain
unaffected by the VCC level.
Design Consideration
When the idle mode is terminated by a hardware reset, the device
normally resumes program execution, from where it left off, up to
two machine cycles before the internal reset algorithm takes
control. On-chip hardware inhibits access to internal RAM in this
event, but access to the port pins is not inhibited. To eliminate the
possibility of an unexpected write when Idle is terminated by reset,
the instruction following the one that invokes Idle should not be
one that writes to a port pin or to external memory.
ONCE
Mode
The ONCE (“On-Circuit Emulation”) Mode facilitates testing and
debugging of systems without the device having to be removed from
the circuit. The ONCE Mode is invoked by:
1. Pull ALE low while the device is in reset and PSEN is high;
2. Hold ALE low as RST is deactivated.
While the device is in ONCE Mode, the Port 0 pins go into a float
state, and the other port pins and ALE and PSEN are weakly pulled
high. The oscillator circuit remains active. While the device is in this
mode, an emulator or test CPU can be used to drive the circuit.
Normal operation is restored when a normal reset is applied.
Programmable Clock-Out
A 50% duty cycle clock can be programmed to come out on P1.0.
This pin, besides being a regular I/O pin, has two alternate
functions. It can be programmed:
1. to input the external clock for Timer/Counter 2, or
2. to output a 50% duty cycle clock ranging from 122 Hz to 8 MHz at
a 16 MHz operating frequency (61 Hz to 4 MHz in 12 clock mode).
To configure the Timer/Counter 2 as a clock generator, bit C/T2 (in
T2CON) must be cleared and bit T20E in T2MOD must be set. Bit
TR2 (T2CON.2) also must be set to start the timer.
The Clock-Out frequency depends on the oscillator frequency and
the reload value of Timer 2 capture registers (RCAP2H, RCAP2L)
as shown in this equation:
Oscillator Frequency
n
(65536
* RCAP2H, RCAP2L)
n =
2 in 6 clock mode
4 in 12 clock mode
Where (RCAP2H,RCAP2L) = the content of RCAP2H and RCAP2L
taken as a 16-bit unsigned integer.
In the Clock-Out mode Timer 2 roll-overs will not generate an
interrupt. This is similar to when it is used as a baud-rate generator.
It is possible to use Timer 2 as a baud-rate generator and a clock
generator simultaneously. Note, however, that the baud-rate and the
Clock-Out frequency will be the same.
Table 2.
External Pin Status During Idle and Power-Down Mode
MODE
PROGRAM MEMORY
ALE
PSEN
PORT 0
PORT 1
PORT 2
PORT 3
Idle
Internal
1
Data
Idle
External
1
Float
Data
Address
Data
Power-down
Internal
0
Data
Power-down
External
0
Float
Data
相關PDF資料 |
PDF描述 |
|---|---|
| 935265441118 | 8-BIT, FLASH, 33 MHz, MICROCONTROLLER, PQCC44 |
| 935265436112 | 8-BIT, FLASH, 33 MHz, MICROCONTROLLER, PQCC44 |
| 935265441518 | 8-BIT, FLASH, 33 MHz, MICROCONTROLLER, PQCC44 |
| 935267813551 | 8-BIT, FLASH, 33 MHz, MICROCONTROLLER, PQFP44 |
| 935267811551 | 8-BIT, FLASH, 33 MHz, MICROCONTROLLER, PQFP44 |
相關代理商/技術參數 |
參數描述 |
|---|---|
| 935267356112 | 制造商:NXP Semiconductors 功能描述:IC TEA1507PN |
| 935268081112 | 制造商:NXP Semiconductors 功能描述:SUB ONLY IC |
| 935268721125 | 制造商:NXP Semiconductors 功能描述:Buffer/Line Driver 1-CH Non-Inverting 3-ST CMOS 5-Pin TSSOP T/R |
| 935269304128 | 制造商:ST-Ericsson 功能描述:IC AUDIO CODEC W/TCH SCRN 48LQFP |
| 935269544557 | 制造商:NXP Semiconductors 功能描述:SUB ONLY TDA9587-2US1-V1.3 |
發(fā)布緊急采購，3分鐘左右您將得到回復。