at89lv55 ATMEL Corporation, at89lv55 Datasheet - Page 10

• Manufacturer Part Number: at89lv55
• Description: At89lv55 8-bit Microcontroller With 20k Bytes Flash
• Manufacturer: ATMEL Corporation

Figure 8-2.
Table 8-2.
10
T2MOD Address = 0C9H
Not Bit Addressable
Symbol
–
T20E
DCEN
Bit
AT89LV55
–
7
Timer 2 Auto Reload Mode (DCEN = 0)
T2MOD—Timer 2 Mode Control Register
Function
Not implemented, reserved for future use.
Timer 2 Output Enable bit.
When set, this bit allows Timer 2 to be configured as an up/down counter.
–
6
A logic 0 at T2EX makes Timer 2 count down. The timer underflows when TH2 and TL2 equal
the values stored in RCAP2H and RCAP2L. The underflow sets the TF2 bit and causes 0FFFFH
to be reloaded into the timer registers.
The EXF2 bit toggles whenever Timer 2 overflows or underflows and can be used as a 17th bit
of resolution. In this operating mode, EXF2 does not flag an interrupt.
–
5
–
4
–
3
–
2
Reset Value = XXXX XX00B
T20E
1
DCEN
0811D–MICRO–3/06
0