qt1100a Quantum Research Group, qt1100a Datasheet - Page 38

• Manufacturer Part Number: qt1100a
• Description: 10 Key Qtouch? Sensor Ic
• Manufacturer: Quantum Research Group

Host Data Output
5.6 SPI Timing Diagram
See Section 5.7 for timing parameters
1. Host first waits for QT1100A to float CRDY high (using pull-up resistor)
2. Host asserts /SS line low
3. Host shifts out byte to QT1100A using 8 falling edges of CLK, on QT1100A pin DI
4. QT1100A shifts data out back to host on the same falling edges of CLK, on QT1100A pin DO
5. QT1100A and host both shift data in on the rising edges of CLK
6. Host releases /SS high
7. CRDY may be pulled low again by QT1100A at any time after /SS is pulled low
8. Host must send nulls to shift out expected return data
(Slave Input - DI)
LQ
(Slave Out - DO)
QT Data Output
CLK from Host
CRDY from QT
/SS from host
3-state
?
pulled (floats) high
?
Data shifts in on rising edge of SCK
7
7
data shifts out on falling edge
T5
6
6
5
5
4
4
Twcrdy
clamped low by QT
3
3
2
2
1
1
0
0
3-state
T6
T9
38
?
? 7
7
6
6
T7
5
5
4
4
3
3
2
2
T8
1
1
Tcyc
0
0
Copyright © 2003-2005 QRG Ltd
QT1100A-ISG R3.02/1105
T4
?
? 7
7
6
6
5
5