SX Users Manual Rev. 3.1
170
© 2000 Scenix Semiconductor, Inc. All rights reserved.
www.scenix.com
Chapter 8 Multi-Function Timers
8.4.2
Timer T1 Control B Register (T1CNTB)
RTCCOV T1CPEDG T1EXEDG
T1PS2-T1PS0
T1MC1-T1MC0
7
6
5
4
3
2
1
0
Table 8-3 T1CNTB Register Bits
Bit Name
Description
RTCCOV
RTCC Overflow Flag. This flag is automatically set to 1 when the Real-Time Clock/Counter
(RTCC) overflows from FFh to 00h. This flag stays set until it is cleared by the software. Note
that this flag is not related to multi-function timers T1 and T2.
T1CPEDG
Timer T1 Capture Edge. This bit sets the edge sensitivity of the Timer T1 input capture pins, Cap-
ture 1 and Capture 2 (RB4 and RB5). Set this bit to 1 to sense positive-going (low-to-high) edges.
Clear this bit to 0 to sense negative-going (high-to-low) edges.
T1EXEDG
Timer T1 External Event Clock Edge. This bit sets the edge sensitivity of the Timer T1 input used
to count external events (RB7). Set this bit to 1 to sense positive-going (low-to-high) edges. Clear
this bit to 0 to sense negative-going (high-to-low) edges.
T1PS2-T1PS0
Timer T1 Prescaler Divider field. This 3-bit field specifies the divide-by factor for generating the
timer clock from the on-chip system clock:
000 = divide by 1
001 = divide by 2
010 = divide by 4
011 = divide by 8
100 = divide by 16
101= divide by 32
110 = divide by 64
111 = divide by 128
For example, setting this field to 010 sets the divide-by factor to 4, which means that the T1
counter register is incremented once every four system clock cycles.
T1MC1-T1MC0
Timer T1 Mode Control field. This 2-bit field specifies the Timer T1 operating mode as follows:
00 = Software Timer mode
01 = PWM mode
10 = Capture/Compare mode
11 = External Event mode