XE8805 SEMTECH [Semtech Corporation], XE8805 Datasheet - Page 64

• Manufacturer Part Number: XE8805
• Description: Data Acquisition MCU
• Manufacturer: SEMTECH [Semtech Corporation]

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
software reset.
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
Note 1: this value is indicative only since it depends on the package.
Table 11-9. Port A electrical specification.
© Semtech 2006
Sym
V
V
R
Cin
INL
INH
PU
description
Input high voltage
Input low voltage
Pull-up resistance
Input capacitance
PARes1[x]
Table 11-8: Selection bits for reset signal
0.7*VBAT
0
0
1
1
VSS
min
20
3.5
typ
50
PARes0[x]
11-5
0.2*VBAT
0
1
0
1
VBAT
max
80
unit Comments
kΩ
pF
V
V
PAReset[x]
not(PA[x])
PA[x]
0
1
VBAT≥2.4V
VBAT≥2.4V
Note 1
XE8805/05A
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