IC MCU OTP 8BIT 1K 20DIP

COP8SAA720N9

Manufacturer Part NumberCOP8SAA720N9
DescriptionIC MCU OTP 8BIT 1K 20DIP
ManufacturerNational Semiconductor
SeriesCOP8™ 8SA
COP8SAA720N9 datasheet
 


Specifications of COP8SAA720N9

Core ProcessorCOP8Core Size8-Bit
Speed10MHzConnectivityMicrowire/Plus (SPI)
PeripheralsPOR, PWM, WDTNumber Of I /o16
Program Memory Size1KB (1K x 8)Program Memory TypeOTP
Ram Size64 x 8Voltage - Supply (vcc/vdd)2.7 V ~ 5.5 V
Oscillator TypeInternalOperating Temperature0°C ~ 70°C
Package / Case20-DIP (0.300", 7.62mm)Lead Free Status / RoHS StatusContains lead / RoHS non-compliant
Eeprom Size-Data Converters-
Other names*COP8SAA720N9
COP8SAA720N9B
COP8SAA720NB
  
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7.0 Timers
(Continued)
7.2.3 Mode 3. Input Capture Mode
The device can precisely measure external frequencies or
time external events by placing the timer block, T1, in the
input capture mode. In this mode, the reload registers serve
as independent capture registers, capturing the contents of
the timer when an external event occurs (transition on the
timer input pin). The capture registers can be read while
maintaining count, a feature that lets the user measure
elapsed time and time between events. By saving the timer
value when the external event occurs, the time of the exter-
nal event is recorded. Most microcontrollers have a latency
time because they cannot determine the timer value when
the external event occurs. The capture register eliminates
the latency time, thereby allowing the applications program
to retrieve the timer value stored in the capture register.
In this mode, the timer T1 is constantly running at the fixed t
rate. The two registers, R1A and R1B, act as capture regis-
ters. Each register acts in conjunction with a pin. The register
R1A acts in conjunction with the T1A pin and the register
R1B acts in conjunction with the T1B pin.
The timer value gets copied over into the register when a
trigger event occurs on its corresponding pin. Control bits,
T1C3, T1C2 and T1C1, allow the trigger events to be speci-
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fied either as a positive or a negative edge. The trigger
condition for each input pin can be specified independently.
The trigger conditions can also be programmed to generate
interrupts. The occurrence of the specified trigger condition
on the T1A and T1B pins will be respectively latched into the
pending flags, T1PNDA and T1PNDB. The control flag
T1ENA allows the interrupt on T1A to be either enabled or
disabled. Setting the T1ENA flag enables interrupts to be
generated when the selected trigger condition occurs on the
T1A pin. Similarly, the flag T1ENB controls the interrupts
from the T1B pin.
Underflows from the timer can also be programmed to gen-
erate interrupts. Underflows are latched into the timer T1C0
pending flag (the T1C0 control bit serves as the timer under-
flow interrupt pending flag in the Input Capture mode). Con-
sequently, the T1C0 control bit should be reset when enter-
ing the Input Capture mode. The timer underflow interrupt is
enabled with the T1ENA control flag. When a T1A interrupt
C
occurs in the Input Capture mode, the user must check both
the T1PNDA and T1C0 pending flags in order to determine
whether a T1A input capture or a timer underflow (or both)
caused the interrupt.
Figure 17 shows a block diagram of the timer in Input Cap-
ture mode.
FIGURE 17. Timer in Input Capture Mode
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