Datasheet

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OPERATION - PORT SCAN
t
coordinate
 7.5 s  t
REF
 4N
AVG

N
BITS
1
ƒ
conv
 4.4 s

(11)
Start Clock
Turn off clock
Convert Battery Input
1
Store Battery Input 1
in BAT1 Register
Set /DAV = 0
Power up ADC
Power Down
Reference
Is Data
Averaging
Done
N
Y
Power Down ADC
DONE
Host Writes A/D
Converter Control
Register
Power Up Reference
(Including Delay)
Convert Battery Input
2
Store Battery Input 2
in BAT2 Register
Is Data
Averaging
Done
N
Y
Convert Auxiliary
Input 1
Store Auxiliary Input
in AUX1 Register
Is Data
Averaging
Done
N
Y
Convert Auxiliary
Input 2
Store Auxiliary Input
2 in AUX2 Register
Is Data
Averaging
Done
N
Y
TSC2301
SLAS371D – SEPTEMBER 2002 – REVISED AUGUST 2004
If measurements of all the battery and auxiliary inputs are required, the port scan mode can be used. This mode
causes the TSC2301 to sample and convert both battery inputs and both auxiliary inputs. At the end of this cycle,
the battery and auxiliary data registers contain the updated values, and the DAV pin is asserted low, signaling
the host to read the data. Thus, with one write to the TSC2301, the host can cause four different measurements
to be made. Because the battery and auxiliary data registers are consecutive in memory, all four registers can be
read in one SPI transaction, as described in Figure 50 .
The flowchart for this process is shown in Figure 69 . The time needed to make a complete port scan is given by:
Port Scan
Figure 69. Port Scan Mode
61