nRF24E2 Nordic VLSI, nRF24E2 Datasheet - Page 69

• Manufacturer Part Number: nRF24E2
• Description: Single Chip RF Transmitter + MCU + ADC NRF2402 2.4GHz RF Transmitter
• Manufacturer: Nordic VLSI

PRODUCT SPECIFICATION
Timer 2 runs only in 16-bit mode and offers several capabilities not available with
Timers 0 and 1. The modes available with Timer 2 are:
The SFRs associated with Timer 2 are:
for capture mode, or as the LSB of the 16-bit reload value when Timer 2 is configured
for auto-reload mode.
for capture mode, or as the MSB of the 16-bit reload value when Timer 2 is
configured for auto-reload mode.
Bit
T2CON.7
T2CON.6
T2CON.5
T2CON.4
T2CON.3
T2CON.2
T2CON.1
T2CON.0
Table 10-16 : T2CON Register – SFR 0xC8
10.8.3.1 Timer 2 Mode Control
Table 10-17 summarizes how the SFR bits determine the Timer 2 mode.
Nordic VLSI ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone [phone] - Fax [phone]
Revision: 1.0
- 16-bit timer/counter
- 16-bit timer with capture
- 16-bit auto-reload timer/counter
- Baud-rate generator
- T2CON – SFR 0xC8; refer to Table 10-16 : T2CON Register – SFR 0x
- RCAP2L – SFR 0xCA – Used to capture the TL2 value when Timer 2 is configured
- RCAP2H – SFR 0xCB – Used to capture the TH2 value when Timer 2 is configured
-
-
TL2 – SFR 0xCC – Lower eight bits of the 16-bit count.
TH2 – SFR 0xCD – Upper eight bits of the 16-bit count.
Function
TF2 - Timer 2 overflow flag. Hardware will set TF2 when Timer 2 overflows from 0xFFFF. TF2 must be
cleared to 0 by the software. TF2 will only be set to a 1 if RCLK and TCLK are both cleared to 0.
Writing a 1 to TF2 forces a Timer 2 interrupt if enabled.
EXF2 - Timer 2 external flag. Hardware will set EXF2 when a reload or capture is caused by a high-to-
low transition on the t2ex pin, and EXEN2 is set. EXF2 must be cleared to 0 by the software. Writing a 1
to EXF2 forces a Timer 2 interrupt if enabled.
RCLK - Receive clock flag. Determines whether Timer 1 or Timer 2 is used for Serial port timing of
received data in serial mode 1 or 3. RCLK = 1 selects Timer 2 overflow as the receive clock. RCLK = 0
selects Timer 1 overflow as the receive clock.
TCLK - Transmit clock flag. Determines whether Timer 1 or Timer 2 is used for Serial port timing of
transmit data in serial mode 1 or 3. TCLK =1 selects Timer 2 overflow as the transmit clock. TCLK = 0
selects Timer 1 overflow as the transmit clock.
EXEN2 - Timer 2 external enable. EXEN2 = 1 enables capture or reload to occur as a result of a high-to-
low transition on t2ex, if Timer 2 is not generating baud rates for the serial port. EXEN2 = 0 causes
Timer 2 to ignore all external events at t2ex.
TR2 - Timer 2 run control flag. TR2 = 1 starts Timer 2. TR2 = 0 stops Timer 2.
C/T2 - Counter/timer select. C/T2 = 0 selects a timer function for Timer 2. C/T2 = 1 selects a counter of
falling transitions on the t2 pin. When used as a timer, Timer 2 runs at four clocks per increment or
twelve clocks per increment as programmed by CKCON.5, in all modes except baud-rate generator
mode. When used in baud-rate generator mode, Timer 2 runs at two clocks per increment, independent of
the state of CKCON.5.
CP/RL2 - Capture/reload flag. When CP/RL2 = 1, Timer 2 captures occur on high-to-low transitions of
t2ex, if EXEN2 = 1. When CP/RL2 = 0, auto-reloads occur when Timer 2 overflows or when high-to-low
transitions occur on t2ex, if EXEN2 = 1. If either RCLK or TCLK is set to 1, CP/RL2 will not function,
and Timer 2 will operate in auto-reload mode following each overflow.
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August 2003