Timer 2 compare mode register (t2cm), Timer 2 compare register 1 (t2co1), Timer 2 compare register 2 (t2co2) byte write – Rainbow Electronics ATAR862-3 User Manual
Page 53: Atar862-3
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53
ATAR862-3
4556B–4BMCU–02/03
Timer 2 Compare Mode
Register (T2CM)
Address: "7"hex - Subaddress: "3"hex
Timer 2 COmpare Register 1
(T2CO1)
Address: "7"hex - Subaddress: "4"hex
In prescaler mode the clock is bypassed if the compare register T2CO1 contains 0.
Timer 2 COmpare Register 2
(T2CO2) Byte Write
Address: "7"hex - Subaddress: "5"hex
Bit 3
Bit 2
Bit 1
Bit 0
T2OTM
T2CTM
T2RM
T2IM
Reset value: 0000b
T2OTM
T
imer
2
O
verflow
T
oggle
M
ask bit
T2OTM = 0, disable overflow toggle
T2OTM = 1, enable overflow toggle, a counter overflow (OVF2) toggles output
flip-flop (TOG2). If the T2OTM-bit is set, only a counter overflow can
generate an interrupt except on the Timer 2 output mode 7.
T2CTM
T
imer
2
C
ompare
T
oggle
M
ask bit
T2CTM = 0, disable compare toggle
T2CTM = 1, enable compare toggle, a match of the counter with the compare
register toggles output flip-flop (TOG2). In Timer 2 output mode 7 and
when the T2CTM-bit is set, only a match of the counter with the
compare register can generate an interrupt.
T2RM
T
imer
2
R
eset
M
ask bit
T2RM = 0, disable counter reset
T2RM = 1, enable counter reset, a match of the counter with the compare register
resets the counter
T2IM
T
imer
2
I
nterrupt
M
ask bit
T2IM = 0, disable Timer 2 interrupt
T2IM = 1, enable Timer 2 interrupt
Timer 2 Output Mode
T2OTM
T2CTM
Timer 2 Interrupt Source
1, 2, 3, 4, 5 and 6
0
x
Compare match (CM2)
1, 2, 3, 4, 5 and 6
1
x
Overflow (OVF2)
7
x
1
Compare match (CM2)
Write cycle
Bit 3
Bit 2
Bit 1
Bit 0
Reset value: 1111b
First write cycle
Bit 3
Bit 2
Bit 1
Bit 0
Reset value: 1111b
Second write cycle
Bit 7
Bit 6
Bit 5
Bit 4
Reset value: 1111b