qt60325 Quantum Research Group, qt60325 Datasheet - Page 17

• Manufacturer Part Number: qt60325
• Description: 32, 48, 64 Key Qmatrix Keypanel Sensor Ics
• Manufacturer: Quantum Research Group

interface in both directions. Unlike hardware SPI slaves,
QT60xx5's need processing time to respond to functions.
DRDY’ is used to let the host know when data is ready for
collection; it indicates to the host when data is ready in
response to a command so that the host can clock over the
data.
This mode requires 5 signals to operate:
MOSI - Master out / Slave in data pin; used as an input for
MISO - Master in / Slave out data pin; used as an output for
SCK - SPI clock - input only clock pin from host. The host
lQ
Get key errors (E), Get keys pushed (K)
MOSI
SCK
Lock Reference Levels ('L') command
{from sensor}
{from sensor}
data from the host at all times. This pin should be
connected to the MOSI pin of the host device.
data to the host at all times. This pin should be connected
to the MISO pin of the host device.
must shift out data on the falling edge of SCK; the
QT60xx5 clocks data in on the rising edge of SCK.
Important note: SCK must idle low just before and after
SS
{from host}
{from host}
{from host}
Calibrate command (all keys)
Setup - Put (affect 64 keys)
Setup - Put (affect 8 keys)
DRDY
Setup - Put (affect 1 key)
MOSI
MISO
SCK
All other commands
SS
from Host to sensor
7 6 5 4 3 2 1 0
Function Type
Command Byte 1
SS, SCK, MOSI originate from Host
Host Command Byte 1
7 6 5 4 3 2 1 0
7 6 5 4 3 2 1 0
Table 4-1 Typical DRDY (Tdr1) Response Delays (Burst Length = 12)
Invalid Data
T cm
T cm
Figure 4-3 SPI Master/Slave Mode Timing
Figure 4-2 SPI Slave-Only Mode Timing
7 6 5 4 3 2 1 0
from host to sensor
Optional Byte 2
7 6 5 4 3 2 1 0
7 6 5 4 3 2 1 0
300ms
800ms
250µs
400us
10ms
40ms
Optional Byte 2
© Quantum Research Group Ltd.
3ms
1ms
Invalid Data
T dr1
Floating
300ms
800ms
300µs
2.7ms
300us
10ms
40ms
1ms
17
SS’ - Slave select - input only; acts as a framing signal to the
DRDY’ - Data Ready - active-low - indicates to the host that
Internal pullup resistors note: The internal pullup resistors
can range from 35k to 120k ohms. If RC filtering is used on
the SPI lines per Figure 4-4, this resistance may not be low
Response Byte or Echo
Response Data or Echo
SS’ transitions either up or down, or the transmission will
fail; between bytes SCK should always idle low. SCK
should never float.
sensor from the host. SS’ must be low before and during
reception of data from the host. It must not go high again
until SCK line has returned low; during data or echo
response it must not go high until after the host has
sensed that DRDY’ has gone high from the device. SS’
must idle high. SS’ has an internal pullup resistor.
the part is ready to send data back subsequent to a
command from the host. This pin idles high. The DRDY’
pin has an internal pullup resistor inside.
7 6 5 4 3 2 1 0
from sensor to host
7 6 5 4 3 2 1 0
Null Dummy Data
T dr1
300ms
800ms
400µs
2.5ms
800us
300us
10ms
40ms
SS, SCK, MOSI originate from sensor
Burst Spacing
T dr3
T dr2
www.qprox.com
300ms
800ms
500µs
2.5ms
800us
300us
10ms
40ms
{N = command dependent}
{N = command dependent}
Nth Byte from sensor
7 6 5 4 3 2 1 0
Nth Response Data
7 6 5 4 3 2 1 0
Null Dummy Data
300ms
800ms
800us
300us
10ms
40ms
T dr3
1ms
2ms
QT60xx5 / R1.05
300ms
800ms
800us
300us
10ms
40ms
2ms
2ms