August 27, 1998
GENERAL RELEASE SPECIFICATION
t
DIS
t
t
DIS
DIS
(MIN)
(MIN)
V
CAP
V
MAX
t
CHG
t
X I
CHG
CHG
V
V
=
X
X
C
X
CHG
COMP
(TCAP)
TOF
OCF
ICF
0
1
2
3
1
2
Point
Action
Software/Hardware Action
Dependent Variable(s)
Begin initial Discharge and select
Mode 2 by clearing CHG and ATD1
and setting ATD2 in the ACR.
Software write.
(ICEN bit also set)
0
1
2
Software.
V
falls to V
.
Wait out minimum t
time.
V
, I , C
CAP
SS
DIS
MAX DIS X.
Stop Discharge and begin Charge
when the next TOF sets the CHG
control bit in ACR.
Timer TOF sets the CHG control bit Free-running Timer
in the ACR. counter overflow, f
, P.
OSC
V
rises to V and comparator
X
CAP
Wait out t
Timer ICF clears the CHG control
bit in the ACR.
time.
CHG
output trips, setting CPF which
causes an ICF from the Timer and
clears the CHG control bit in ACR.
3
V , I
, C
X
CHG X.
Figure 15-10. A/D Conversion - TOF/ICF Control (Mode 2)
MC68HC05SB7
REV 2.1
ANALOG SUBSYSTEM
MOTOROLA
15-25
FREESCALE [ Freescale ]
