sx1511iultrt Semtech Corporation, sx1511iultrt Datasheet - Page 18

• Manufacturer Part Number: sx1511iultrt
• Description: World
• Manufacturer: Semtech Corporation

ADVANCED COMMUNICATIONS & SENSING
4.6.4
Each IO’s polarity can be individually inverted by setting corresponding bit in RegPolarity register. Please note
that polarity inversion can also be combined with level shifting feature.
4.7
At start-up, the transition detection logic is reset, and NINT is released to a high-impedance state. The interrupt
mask register is set to 0xFF, disabling the interrupt output for transitions on all I/O ports. The transition flags are
cleared to indicate no data changes.
An interrupt NINT can be generated on any programmed combination of I/Os rising and/or falling edges through
the RegInterruptMask and RegSense registers.
If needed, the I/Os which triggered the interrupt can then be identified by reading RegInterruptSource register.
When NINT is low (i.e. interrupt occurred), it can be reset back high (i.e. cleared) by writing 0xFF in
RegInterruptSource (this will also clear corresponding bits in RegEventStatus register).
The interrupt can also be cleared automatically when reading RegData register (Cf. RegMisc)
Example: We want to detect rising edge of I/O[1] on SX1511 (NINT will go low).
Rev 1 – 24
Interrupt (NINT)
Polarity Inverter
th
140.000
120.000
100.000
28
26
24
22
20
18
16
14
80.000
60.000
40.000
20.000
0.000
Feb. 2010
1
1.000
IO Output Delay vs. Supply Voltage ( LowDriveEn=0, 20pF Load)
1.5
SX1511 Digital Core Delay vs. Supply Voltage
1.500
2
Figure 12 – Level Shifter Max Frequency Calculation Data
2.000
Typical
Typical
VDDM (V)
VCCx (V)
2.5
Worst Case
2.500
Worst Case
10.000
9.000
8.000
7.000
6.000
5.000
4.000
3.000
2.000
1.000
0.000
1.000
3.000
3
1.500
3.500
IO Input Delay vs. Supply Voltage
3.5
2.000
Typical
18
VCCx (V)
2.500
Worst Case
140.000
120.000
100.000
28
26
24
22
20
18
16
14
80.000
60.000
40.000
20.000
0.000
1
1.000
World’s Lowest Voltage Level Shifting GPIO
3.000
IO Output Delay vs. Supply Voltage (LowDriveEn=1, 20pF Load)
SX1512 Digital Core Delay vs. Supply Voltage
1.5
1.500
3.500
with LED Driver and Keypad Engine
SX1510/SX1511/SX1512
2
2.000
Typical
Typical
VDDM (V)
VCCx (V)
2.5
Worst Case
2.500
Worst Case
3.000
3
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3.500
3.5