VRS51C1000-40-PG Ramtron, VRS51C1000-40-PG Datasheet - Page 20

• Manufacturer Part Number: VRS51C1000-40-PG
• Description: Microcontrollers (MCU) 64K+1K 40MHz 5V
• Manufacturer: Ramtron

Specifications of VRS51C1000-40-PG

• Data Bus Width: 8 bit
• Program Memory Type: Flash
• Program Memory Size: 64 KB
• Data Ram Size: 1 KB
• Interface Type: UART
• Maximum Clock Frequency: 40 MHz
• Number Of Programmable I/os: 36
• Number Of Timers: 3
• Operating Supply Voltage: 4.5 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• Package / Case: PDIP-40
• Minimum Operating Temperature: - 40 C
• Lead Free Status / Rohs Status: Details

Timer 2 Capture Mode
In Capture Mode, the EXEN2 bit of the T2CON register
controls whether an external transition on the T2EX pin
will trigger capture of the timer value.
When EXEN2 = 0, Timer 2 acts as a 16-bit timer or
counter, which, upon overflowing, will set the TF2 bit
(Timer 2 overflow bit). This overflow can be used to
generate an interrupt.
When EXEN2 = 1, the above still applies, however, in
addition, it is possible to allow a 1 to 0 transition at the
T2EX input to cause the current value stored in the
Timer 2 registers (TL2 and TH2) to be captured into
the RCAP2L and RCAP2H registers. Furthermore, the
transition at T2EX causes bit EXF2 in T2CON to be
set, and EXF2, like TF2, can generate an interrupt.
Note that both EXF2 and TF2 share the same interrupt
vector.
Timer 2 Auto-Reload Mode
In this mode, there are also two options controlled by
the EXEN2 bit in the T2CON register.
If EXEN2 = 0, when Timer 2 rolls over, it not only sets
TF2, but also causes the Timer 2 registers to be
reloaded with the 16-bit value in the RCAP2L and
RCAP2H registers previously initialised. In this mode,
Timer 2 can be used as a baud rate generator source
for the serial port.
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F
IGURE
VRS51C1000
T2EX pin
T2 pin
F
OSC
13: T
IMER
EXEN2
÷12
2
IN
C/T2
C
APTURE
0
1
TR2
COUNTER
M
TIMER
ODE
0
0
RCAP2L
TL2
7
7
0
0
EXF2
RCAP2H
TH2
7
Interrupt
7
Timer 2
TF2
If EXEN2=1, Timer 2 still performs the above
operation, however, additionally, a 1 to 0 transition at
the external T2EX input will also trigger an anticipated
reload of Timer 2 with the value stored in RCAP2L,
RCAP2H and set EXF2.
F
IGURE
T2 pin
T2EX pin
F
OSC
14: T
IMER
EXEN2
÷12
2
C/T2
IN AUTO
0
1
-
RELOAD MODE
TR2
COUNTER
TIMER
0
0
page 20 of 48
RCAP2L
TL2
7
7
0
0
EXF2
RCAP2H
TH2
7
Interrupt
7
Timer 2
TF2