SX8801IRXXMLTRT View Datasheet(PDF) - Semtech Corporation
Part Name
Description
MFG CO.
'SX8801IRXXMLTRT' PDF : 135 Pages View PDF
XE8801A – SX8801R
Port A as an event source:
The interrupt signals of the pins PA[0] and PA[1] are also available as events on the event controller.
PortA as a clock source (product dependent):
Images of the PA[0] to PA[3] input ports (debounced or not) are available as clock sources for the
counter/timer/PWM peripheral (see the counter block documentation for more information).
Port A as a reset source:
Port A can be used to generate a system reset by placing a predetermined word on Port A externally. The reset is
built using a logical and of the 8 PARes[x] signals:
resetfromportA = PAReset[7] AND PAReset[6] AND PAReset[5] AND ... AND PAReset[0]
PAReset[x] is itself a logical function of the corresponding pin PA[x]. One of four logical functions can be selected
for each pin by writing into two registers RegPARes0 and RegPARes1 as shown in Table 11-8.
PARes1[x]
0
0
1
1
PARes0[x]
0
1
0
1
PAReset[x]
0
PA[x]
not(PA[x])
1
Table 11-8: Selection bits for reset signal
A reset from Port A can be inhibited by placing a 0 on both PARes1[x] and PARes0[x] for at least 1 pin. Setting
both PARes1[x] and PARes0[x] to 1, makes the reset independent of the value on the corresponding pin. Setting
both registers to hFF, will reset the circuit independent from the Port A input value. This makes it possible to do a
reset by software.
Note: depending of the value of PA[0] to PA[7], the change of RegPARes0 and RegPARes1 can cause a reset.
Therefore it is safe to have always one (RegPARes0[x], RegPARes1[x]) equal to ‘00’ during the setting operations.
Port A as a RC enable:
PA[0] can be used to enable the RC oscillator. When RCOnPA0 bit in RegSysMisc is set to 1 and the value of
PA[0] (debounced or not) is equal to 1, the EnRc bit in RegSysClock is automatically set to 1.
11.6 Port A electrical specification
Sym
VINH
VINL
RPU
Cin
description
Input high voltage
Input low voltage
Pull-up resistance
Input capacitance
min
typ
max unit Comments
0.7*VBAT
VBAT
V
VBAT≥2.4V
VSS
0.2*VBAT V
VBAT≥2.4V
20
50
80
kΩ
3.5
pF
Note 1
Note 1: this value is indicative only since it depends on the package.
Table 11-9. Port A electrical specification.
© Semtech 2005
11-5
www.semtech.com
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