Datasheet

Philips Semiconductors Product specification
8XC54/58
8XC51FA/FB/FC/80C51FA
8XC51RA+/RB+/RC+/RD+/80C51RA+
80C51 8-bit microcontroller family
8K–64K/256–1K OTP/ROM/ROMless, low voltage (2.7V–5.5V),
low power, high speed (33MHz)
2000 Aug 07
15
Table 4. Timer 2 Operating Modes
RCLK + TCLK CP/RL2 TR2 MODE
0 0 1 16-bit Auto-reload
0 1 1 16-bit Capture
1 X 1 Baud rate generator
X X 0 (off)
OSC
÷ 12
C/T2
= 0
C/T2
= 1
TR2
Control
TL2
(8-bits)
TH2
(8-bits)
TF2
RCAP2L RCAP2H
EXEN2
Control
EXF2
Timer 2
Interrupt
T2EX Pin
Transition
Detector
T2 Pin
Capture
SU00066
Figure 2. Timer 2 in Capture Mode
Not Bit Addressable
Symbol Function
— Not implemented, reserved for future use.*
T2OE Timer 2 Output Enable bit.
DCEN Down Count Enable bit. When set, this allows Timer 2 to be configured as an up/down counter.
— — — — — — T2OE DCEN
SU00729
76543210
* User software should not write 1s to reserved bits. These bits may be used in future 8051 family products to invoke new features.
In that case, the reset or inactive value of the new bit will be 0, and its active value will be 1. The value read from a reserved bit is
indeterminate.
Bit
T2MOD Address = 0C9H Reset Value = XXXX XX00B
Figure 3. Timer 2 Mode (T2MOD) Control Register