Datasheet

Page 23 of 161
nRF8001 Product Specification
Revision 1.2
7.1.3.1 RDYn line
The application controller must, at all times, have the RDYn line configured as input with pull-up drivers. At
power on reset and wake up from sleep scenarios, the RDYn level is valid after 62 ms from reset or wake
up.
Figure 9. RDYn line functionality
Note: The supply rise time is not included in the power up sequence shown in Figure 9.
7.1.4 ACI command exchange
Figure 10. shows the signaling in an ACI command sent from the application controller to nRF8001.
Figure 10. Data exchange from an application controller to nRF8001
The following procedure is performed when the application controller sends a command to nRF8001:
1. The application controller requests the right to send data by setting the REQN pin to ground.
2. nRF8001 sets the RDYN pin to ground when it is ready to receive data.
3. The application controller starts sending data on the MOSI pin:
• Byte 1 (length byte) from the application controller defines the length of the message.
• Byte 2 (ACI byte1) is the first byte of the ACI data.
• Byte N is the last byte of the ACI data.
• The application controller sets the REQN pin high to terminate the data transaction.
Note: The maximum length of a command packet is 32 bytes, including the length byte. MOSI shall
be held low if the application controller receives an event and has no message to send to the
nRF8001.
Not defined
RDYn
RESET
62 ms
MISO
MOSI
SCK
RDYN
REQN
length ACI byte1 ACI byte2
Request
transmission
Slave ready
End of
transmission
ACI byteN
....
....
....