Windowed Mode (#S 5A & 5B) - NXP Semiconductors MC9S08SU16 Reference Manual

CMP Functional Description
EN, PMODE,HYSTCTR
INP
INM
bus clock
FILT_PER
Figure 18-7. Sampled, Filtered (# 4B): Sampling point internally derived
The only difference in operation between Sampled, Non-Filtered (# 3B) and Sampled,
Filtered (# 4B) is that CR0[FILTER_CNT] is now greater than 1, which activates filter
operation.
18.11.1.5 Windowed Mode (#s 5A & 5B)
The following figure illustrates comparator operation in the windowed mode, ignoring
latency of the analog comparator, polarity select and Window Control block. It also
assumes that the Polarity Select is set to "non-inverting". Note that the analog comparator
output is passed to COUTA only when the WINDOW signal is high.
In actual operation, COUTA may lag the analog inputs by up to one bus clock cycle plus
the combinational path delay through the comparator and polarity select logic.
308
INTERNAL BUS
FILT_PER
COS INV
+
+
Polarity
Select
-
-
CMPO
WINDOW/SAMPLE
Clock
divided
Prescaler
bus
clock
MC9S08SU16 Reference Manual, Rev. 5, 4/2017
OPE
FILTER_CNT SE COUT
WE
>
0x01
0
1
Window
Filter
Control
Block
1
0
COUTA
CGMUX
SE=0
IER/F CFR/F
Interrupt
Control
IRQ
COUT
(TO OTHER SOC FUNCTIONS))
0
CMPO to
1
PAD
COS
NXP Semiconductors