73S1209F Maxim, 73S1209F Datasheet - Page 51

• Manufacturer Part Number: 73S1209F
• Description: The 73S1209F is a self-contained, SoC smart card reader IC that is an ideal solution for serially connected ISO 7816 design
• Manufacturer: Maxim

DS_1209F_004
1.7.8
The 73S1209F includes a programmable comparator that is connected to the ANA_IN pin. The
comparator can be configured to trigger an interrupt if the input voltage rises above or falls below a
selectable threshold voltage. The comparator control register should not be modified when the analog
interrupt (ANAIEN bit in the
generated when modifying the threshold. The comparator has a built-in hysteresis to prevent the
comparator from repeatedly responding to low-amplitude noise. This hysteresis is approximately 20mV.
Interrupt control is handled in the
Rev. 1.2
Analog Compare Control Register (ACOMP): 0xFFD0
ACOMP.7
ACOMP.6
ACOMP.5
ACOMP.4
ACOMP.3
ACOMP.2
ACOMP.1
ACOMP.0
Bit
Analog Voltage Comparator
MSB
ANALVL
ANALVL
ONCHG
Symbol
CMPEN
TSEL.2
TSEL.1
TSEL.0
CPOL
-
–
INT6Ctl
When read, indicates whether the input level is above or below the
threshold. This is a real time value and is not latched, so it may change
from the time of the interrupt trigger until read.
If set, the Ana_interrupt is invoked on any change above or below the
threshold, bit 4 is ignored.
If set = 1, Ana_interrupt is invoked when signal rises above selected
threshold. If set = 0, Ana_interrupt is invoked when signal goes below
selected threshold (default).
Enables power to the analog comparator. 1= Enabled. 0 = Disabled
(default).
Sets the voltage threshold for comparison to the voltage on pin
ANA_IN. Thresholds are as follows:
TSEL.2
ONCHG
INT6Ctl
0
0
0
0
1
1
1
1
register) is enabled to guard against any false interrupt that might be
Table 55: The ACOMP Register
register.
CPOL
TSEL.1
0
0
1
1
0
0
1
1
CMPEN TSEL.2 TSEL.1 TSEL.0
TSEL.0
0
1
0
1
0
1
0
1
0x00
Function
Voltage Threshold
1.00V
1.24V
1.40V
1.50V
1.75V
2.00V
2.30V
2.50V
73S1209F Data Sheet
LSB
51