Acknowledges receipt of a valid DATA frame.
[CONTROL, CRC high, CRC low, FLAG]
Notation used in documentation: ACK(A)+/-
Examples:
Sent by: NCP, Host
Carries all EZSP frames.
[CONTROL, EZSP 0, EZSP 1, EZSP 2, EZSP n, CRC high, CRC low, FLAG]
Notation used in documentation: DATA(F, A, R)
Example without pseudo-random sequence applied to Data Field:
Example with pseudo-random sequence applied to Data Field:
Sent by: NCP, Host
Informs the Host that the NCP detected a fatal error and is in the FAILED state.
[CONTROL, version, error code, CRC high, CRC low, FLAG]
Notation used in documentation: ERROR(V, C )
Example: C2 01 52 FA BD 7E
Sent by: NCP
Indicates receipt of a DATA frame with an error or that was discarded due to lack of memory.
[CONTROL, CRC high, CRC low, FLAG]
Notation used in documentation: NAK(A)+/-
Examples:
Sent by: NCP, Host
Requests the NCP to perform a software reset (valid even if the NCP is in the FAILED state).
[CONTROL, CRC high, CRC low, FLAG]
Notation used in documentation: RST()
Example: C0 38 BC 7E
Sent by: Host
Informs the Host that the NCP has reset and the reason for the reset.
[CONTROL, version, reset code, CRC high, CRC low, FLAG]
Notation used in documentation: RSTACK(V, C)
Example: C1 02 02 9B 7B 7E
Sent by: NCP
Identify the type of frame from control byte.
Control byte formats +---------+----+----+----+----+----+----+----+----++---------+ | | B7 | B6 | B5 | B4 | B3 | B2 | B1 | B0 || Range | +---------+----+----+----+----+----+----+----+----++---------+ | DATA | 0 | frameNum | rF | ackNum ||0x00-0x7F| +---------+----+----+----+----+----+----+----+----++---------+ | ACK | 1 | 0 | 0 | pF | nF | ackNum ||0x80-0x9F| | NAK | 1 | 0 | 1 | pF | nF | ackNum ||0xA0-0xBF| +---------+----+----+----+----+----+----+----+----++---------+ | RST | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 || 0xC0 | | RSTACK | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 1 || 0xC1 | | ERROR | 1 | 1 | 0 | 0 | 0 | 0 | 1 | 0 || 0xC2 | +---------+----+----+----+----+----+----+----+----++---------+ rF = rFlag (retransmission flag) nF = nFlag (receiver not ready flag, always 0 in frames sent by the NCP) pF = flag reserved for future use frameNum = DATA frame’s 3-bit sequence number ackNum = acknowledges receipt of DATA frames up to, but not including, ackNum Control byte values 0xC3-0xFE are unused, 0xFF is reserved.