PIC17C42 Microchip Technology, PIC17C42 Datasheet - Page 70

• Manufacturer Part Number: PIC17C42
• Description: High-Performance 8-Bit CMOS EPROM/ROM Microcontroller
• Manufacturer: Microchip Technology

PIC17C4X
FIGURE 11-5: TMR0 READ/WRITE IN TIMER MODE
TABLE 11-1:
DS30412C-page 70
Address
05h, Unbanked
06h, Unbanked
07h, Unbanked
0Bh, Unbanked
0Ch, Unbanked
Legend:
Note 1:
WR_TMR0H
WR_TRM0L
RD_TMR0L
x = unknown, u = unchanged, - = unimplemented read as a '0', q - value depends on condition, Shaded cells are not used by Timer0.
Other (non power-up) resets include: external reset through MCLR and the Watchdog Timer Reset.
AD15:AD0
Instruction
Instruction
executed
TMR0H
TMR0L
fetched
Name
T0STA
CPUSTA
INTSTA
TMR0L
TMR0H
ALE
REGISTERS/BITS ASSOCIATED WITH TIMER0
Q1
DATAL,TMR0L
TMR0 register; low byte
TMR0 register; high byte
Write TMR0L
INTEDG
Previously
Fetched
Instruction
Bit 7
PEIF
MOVFP
—
Q2 Q3
FE
12
In this example, old TMR0 value is 12FEh, new value of AB56h is written.
T0CKIF
Q4
T0SE
Bit 6
—
DATAH,TMR0H
Q1
Write TMR0H
DATAL,TMR0L
Write TMR0L
MOVFP
FF
Q2 Q3
MOVFP
12
STKAV
T0CS
Bit 5
T0IF
Q4
GLINTD
Q1
DATAH,TMR0H
Read TMR0L
Write TMR0H
INTF
Bit 4
PS3
TMR0L,W
13
56
MOVPF
MOVFP
Q2 Q3
PEIE
Bit 3
PS2
TO
Q4
Q1
Read TMR0L
Read TMR0L
T0CKIE
AB
TMR0L,W
TMR0L,W
Bit 2
MOVPF
PS1
Q2 Q3
PD
MOVPF
Q4
Bit 1
T0IE
PS0
—
Q1
Read TMR0L
Read TMR0L
TMR0L,W
TMR0L,W
MOVPF
57
INTE
Bit 0
Q2 Q3
MOVPF
—
—
1996 Microchip Technology Inc.
Q4 Q1
0000 000-
--11 11--
0000 0000
xxxx xxxx
xxxx xxxx
Power-on
Value on
Reset
Read TMR0L
Read TMR0L
TMR0L,W
TMR0L,W
58
MOVPF
Q2 Q3
MOVPF
other resets
Value on all
0000 000-
--11 qq--
0000 0000
uuuu uuuu
uuuu uuuu
Q4
(Note1)