TC1796
Peripheral Units (Vol. 2 of 2)
Analog-to-Digital Converter (ADC)
User’s Manual
25-40
V2.0, 2007-07
ADC, V2.0
shows the selectable parameters for limit check.
Figure 25-20 Limit Checking
The A/D Converter’s measuring range is divided into the following three areas:
•
Area I: From 000
H
to (including) the lower boundary
•
Area II: excluding the lower boundary to (including) the upper boundary
•
Area III: excluding the upper boundary to top (top due to the selected resolution)
The value stored in LCCONn.BOUNDARY represents a boundary, that is selected by the
channel-specific bit fields CHCONn.BSELA/B. Neither boundary A (selected by
CHCONn.BSELA) nor boundary B (selected by CHCONn.BSELB) is fixed in its
assignment as a lower or upper one. The boundary’s value specifies whether it is
assumed to be the upper or lower one.
In this example, channel number 5 is configured for limit checking. CHCON5.BSELA is
set to 10
B
and selects the boundary stored in LCCON2.BOUNDARY. CHCON5.BSELB
is configured to 01
B
and selects the boundary stored in LCCON1.BOUNDARY. Since the
value of LCCON1.BOUNDARY is above than the value of LCCON2.BOUNDARY, it is
assumed to be the upper one while the boundary stored in LCCON2.BOUNDARY is the
lower one.
000
H
top
LCC
Description
MCA06023
0 0 0
0 0 1
0 1 0
0 1 1
Neither Limit Check nor Interrupt
Not in Area I
Not in Area II
Not in Area III
1 0 0
1 0 1
1 1 0
1 1 1
Interrupt on Write Conv. Result
In Area I
In Area II
In Area III
Area III
LCCON1.Boundary
Area II
LCCON2.Boundary
Area I