86
AT94KAL Series FPSLIC
Rev. 1138G–FPSLI–11/03
Figure 49.
Timer/Counter2 Prescaler
Special Function I/O Register – SFIOR
• Bits 7..2 - Res: Reserved Bits
These bits are reserved bits in the FPSLIC and are always read as zero.
• Bit 1 - PSR2: Prescaler Reset Timer/Counter2
When this bit is set (one) the Timer/Counter2 prescaler will be reset. The bit will be cleared by
the hardware after the operation is performed. Writing a zero to this bit will have no effect. This
bit will always be read as zero if Timer/Counter2 is clocked by the internal CPU clock. If this bit
is written when Timer/Counter2 is operating in asynchronous mode; however, the bit will
remain as one until the prescaler has been reset. See “Asynchronous Operation of
Timer/Counter2” on page 94 for a detailed description of asynchronous operation.
• Bit 0 - PSR10: Prescaler Reset Timer/Counter1 and Timer/Counter0
When this bit is set (one) the Timer/Counter1 and Timer/Counter0 prescaler will be reset. The
bit will be cleared by the hardware after the operation is performed. Writing a zero to this bit
will have no effect. Note that Timer/Counter1 and Timer/Counter0 share the same prescaler
and a reset of this prescaler will affect both timers. This bit will always be read as zero.
8-bit
Timers/Counters
T/C0 and T/C2
Figure 50 shows the block diagram for Timer/Counter0. Figure 51 shows the block diagram for
Timer/Counter2.
Bit
7
6
5
4
3
2
1
0
$30 ($50)
-
-
-
-
-
-
PSR2
PSR10
SFIOR
Read/Write
R
R
R
R
R
R
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
10-BIT T/C PRESCALER
TIMER/COUNTER2 CLOCK SOURCE
CK
PCK2
TOSC1
AS2
CS20
CS21
CS22
PCK2/8
PCK2/64
PCK2/128
PCK2/1024
PCK2/256
PCK2/32
0
PSR2
Clear
TCK2