P89C668 Philips Semiconductors, P89C668 Datasheet - Page 12

• Manufacturer Part Number: P89C668
• Description: 80C51 8-bit Flash microcontroller family 64KB ISP FLASH with 8KB RAM
• Manufacturer: Philips Semiconductors

Philips Semiconductors
Table 4. Timer 2 Operating Modes
2001 Jul 27
80C51 8-bit Flash microcontroller family
64KB ISP Flash with 8KB RAM
*
T2EX Pin
RCLK + TCLK
Symbol
—
T2OE
DCEN
T2 Pin
T2MOD
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.
OSC
X
0
0
1
Not Bit Addressable
Address = 0C9H
Function
Not implemented, reserved for future use.*
Timer 2 Output Enable bit.
Down Count Enable bit. When set, this allows Timer 2 to be configured as an up/down counter.
Bit
6
Transition
Detector
—
7
C/T2 = 0
C/T2 = 1
CP/RL2
X
X
0
1
EXEN2
—
6
Figure 3. Timer 2 Mode (T2MOD) Control Register
Control
Figure 2. Timer 2 in Capture Mode
TR2
—
5
Control
Capture
—
TR2
4
1
1
1
0
12
RCAP2L
(8-bits)
TL2
—
3
16-bit Auto-reload
16-bit Capture
Baud rate generator
(off)
(8-bits)
RCAP2H
TH2
—
2
T2OE
1
EXF2
TF2
MODE
Reset Value = XXXX XX00B
DCEN
0
P89C668
Preliminary data
SU01210
SU00729
Interrupt
Timer 2