Philips Semiconductors
Product data
P87C51RA2/RB2/RC2/RD2
80C51 8-bit microcontroller family 8KB/16KB/32KB/64KB OTP
with 512B/1KB RAM, low voltage (2.7 to 5.5 V), low power, high
speed (30/33 MHz)
2003 Jan 24
17
Table 3.
Timer 2 Operating Modes
RCLK + TCLK
CP/RL2
TR2
MODE
0
1
16-bit Auto-reload
0
1
16-bit Capture
1
X
1
Baud rate generator
X
0
(off)
OSC
÷ n*
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
SU01252
* n = 6 in 6-clock mode, or 12 in 12-clock mode.
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
76
54
32
1
0
*
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