
Data Sheet
ADuC7019/20/21/22/24/25/26/27/28/29
Rev. F | Page 87 of 104
Table 180. T1CON MMR Bit Descriptions
Bit
Value
Description
31:18
Reserved.
17
Event select bit. Set by user to enable time
capture of an event. Cleared by user to
disable time capture of an event.
16:12
Event select range, 0 to 31. These events are
becomes Event 0 for the purposes of
Timer1.
11:9
Clock select.
000
Core clock (HCLK).
001
External 32.768 kHz crystal.
010
P1.0 rising edge triggered.
011
P0.6 rising edge triggered.
8
Count up. Set by user for Timer1 to count
up. Cleared by user for Timer1 to count
down by default.
7
Timer1 enable bit. Set by user to enable
Timer1. Cleared by user to disable Timer1 by
default.
6
Timer1 mode. Set by user to operate in
periodic mode. Cleared by user to operate in
free-running mode. Default mode.
5:4
Format.
00
Binary.
01
Reserved.
10
Hr: min: sec: hundredths (23 hours to 0 hour).
11
Hr: min: sec: hundredths (255 hours to 0
hour).
3:0
Prescale.
0000
Source Clock/1.
0100
Source Clock/16.
1000
Source Clock/256.
1111
Source Clock/32,768.
Table 181. T1CLRI Register
Name
Address
Default Value
Access
T1CLRI
0xFFFF032C
0xFF
W
T1CLRI is an 8-bit register. Writing any value to this register
clears the Timer1 interrupt.
Table 182. T1CAP Register
Name
Address
Default Value
Access
T1CAP
0xFFFF0330
0x00000000
R/W
T1CAP is a 32-bit register. It holds the value contained in
T1VAL when a particular event occurs. This event must be
selected in T1CON.
Timer2 (Wake-Up Timer)
Timer2 is a 32-bit wake-up timer (count down or count up)
with a programmable prescaler. The source can be the 32 kHz
external crystal, the core clock frequency, or the internal 32 kHz
oscillator. The clock source can be scaled by a factor of 1, 16,
256, or 32,768. The wake-up timer continues to run when the
core clock is disabled.
The counter can be formatted as plain 32-bit value or as
hours: minutes: seconds: hundredths.
04955-
036
INTERNAL
OSCILLATOR
EXTERNAL
CRYSTAL
HCLK
PRESCALER
/1, 16, 256
OR 32,768
32-BIT
UP/DOWN
COUNTER
32-BIT
LOAD
TIMER2
VALUE
TIMER2 IRQ
Figure 79. Timer2 Block Diagram
The Timer2 interface consists of four MMRs: T2LD, T2VAL,
T2CON, and T2CLRI.
Table 183. T2LD Register
Name
Address
Default Value
Access
T2LD
0xFFFF0340
0x00000000
R/W
T2LD is a 32-bit register load register.
Table 184. T2VAL Register
Name
Address
Default Value
Access
T2VAL
0xFFFF0344
0xFFFFFFFF
R
T2VAL is a 32-bit read-only register that represents the current
state of the counter.
Table 185. T2CON Register
Name
Address
Default Value
Access
T2CON
0xFFFF0348
0x0000
R/W
T2CON is the configuration MMR described in
Table 186.