Rainbow Electronics AT42QT1110-AZ - Manual (Page 15)

15
9570H–AT42–02/10
AT42QT1110-MZ/AT42QT1110-AZ
4.1.5.2 Get Instructions
Get instructions are instructions that read the data from a location in the QT1110 memory map.
Figure 4-7. Positive Recalibration Delay Get Instruction – CRC Disabled
The host sends the appropriate “Get” command, followed by a “Null” byte. The QT1110 returns
the contents of the addressed memory location.
Figure 4-7 on page 15 shows the exchange for a report on the positive recalibration delay
(assuming that the data byte is 0x0C).
With CRC Enabled, this exchange takes 4 bytes, with a command CRC transmitted by the host
and a report CRC returned by the QT1110 (see
Figure 4-8 ).
Figure 4-8. Positive Recalibration Delay Get Instruction – CRC Enabled
Host (Sends on MOSI)
Command: 0xD5
Null: 0x00
“Get” Data: 0x0C (Positive Recalibration Delay)
Simultaneous
Transmission Response: 0x55 ( Idle” Fresh Command) “ –
Device (Responds on MISO)
Host (Sends on MOSI)
Command: 0xD5
Null: 0x00
Null: 0x00
“Get” CRC: 0xA3
Simultaneous
Transmission
Command CRC: 0x68
Response: 0x68 (Expected Command CRC)
“Get” Data: 0x0C (Positive Recalibration Delay)
Response: 0x55 ( Idle” Fresh Command) “ –
Device (Responds on MISO)