Ash#

ashDecodeInProgress#

bool ashDecodeInProgress

set false to start decoding a new frame

ashAckTimer#

uint16_t ashAckTimer

rec'd ack timer (msecs)

ashAckPeriod#

uint16_t ashAckPeriod

rec'd ack timer period (msecs)

ashNrTimer#

uint8_t ashNrTimer

not ready timer (16 msec units)

ashEncodeByte#

uint8_t ashEncodeByte (uint8_t len, uint8_t byte, uint8_t * offset)

Builds an ASH frame.

Byte stuffs the control and data fields as required, computes and appends the CRC and adds the ending flag byte. Called with the next byte to encode, this function may return several output bytes before it's ready for the next byte.

Returns

• next encoded output byte in frame.

ashDecodeByte#

EzspStatus ashDecodeByte (uint8_t byte, uint8_t * out, uint8_t * outLen)

Decodes and validates an ASH frame.

Data is passed to it one byte at a time. Decodes byte stuffing, checks crc, finds the end flag and (if enabled) terminates the frame early on CAN or SUB bytes. The number of bytes output will not exceed the max valid frame length, which does not include the flag or the crc.

Returns

• status of frame decoding

  • ::EZSP_SUCCESS

  • ::EZSP_ASH_IN_PROGRESS

  • ::EZSP_ASH_CANCELLED

  • ::EZSP_ASH_BAD_CRC

  • ::EZSP_ASH_COMM_ERROR

  • ::EZSP_ASH_TOO_SHORT

  • ::EZSP_ASH_TOO_LONG

ashRandomizeArray#

uint8_t ashRandomizeArray (uint8_t seed, uint8_t * buf, uint8_t len)

Randomizes array contents by XORing with an 8-bit pseudo random sequence.

This reduces the likelihood that byte-stuffing will greatly increase the size of the payload. (This could happen if a DATA frame contained repeated instances of the same reserved byte value.)

Returns

• last value of the sequence. If a buffer is processed in two or more chunks, as with linked buffers, this value should be passed back as the value of the seed argument

ashStartAckTimer#

void ashStartAckTimer (void )

Sets ashAckTimer to the specified period and starts it running.

ashAckTimerHasExpired#

bool ashAckTimerHasExpired (void )

Indicates whether or not ashAckTimer has expired.

If the timer is stopped then it is not expired.

Returns

• bool

ashAdjustAckPeriod#

void ashAdjustAckPeriod (bool expired)

Adapts the acknowledgement timer period to the observed ACK delay.

If the timer is not running, it does nothing. If the timer has expired, the timeourt period is doubled. If the timer has not expired, the elapsed time is fed into simple IIR filter: T[n+1] = (7*T[n] + elapsedTime) / 8 The timeout period, ashAckPeriod, is limited such that: ASH_xxx_TIME_DATA_MIN <= ashAckPeriod <= ASH_xxx_TIME_DATA_MAX, where xxx is either HOST or NCP.

The acknowledgement timer is always stopped by this function.

ashStartNrTimer#

void ashStartNrTimer (void )

Starts the Not Ready timer.

On the host, this times nFlag refreshing when the host doesn't have room for callbacks for a prolonged period.

On the NCP, if this times out the NCP resumes sending callbacks.

ashNrTimerHasExpired#

bool ashNrTimerHasExpired (void )

Tests whether the Not Ready timer has expired or has stopped.

If expired, it is stopped.

Returns

• true if the Not Ready timer has expired or stopped

ashStopAckTimer#

#define ashStopAckTimer

(void)

Stops and clears ashAckTimer.

ashAckTimerIsRunning#

#define ashAckTimerIsRunning

()

Indicates whether or not ashAckTimer is currently running.

The timer may be running even if expired.

ashAckTimerIsNotRunning#

#define ashAckTimerIsNotRunning

()

Indicates whether or not ashAckTimer is currently running.

The timer may be running even if expired.

ashSetAckPeriod#

#define ashSetAckPeriod

(msec)

Sets the acknowledgement timer period (in msec) and stops the timer.

ashGetAckPeriod#

#define ashGetAckPeriod

()

Returns the acknowledgement timer period (in msec).

ashSetAndStartAckTimer#

#define ashSetAndStartAckTimer

(msec)

Sets the acknowledgement timer period (in msec), and starts the timer running.

ASH_NR_TIMER_BIT#

#define ASH_NR_TIMER_BIT

4

log2 of msecs per NR timer unit

ashStopNrTimer#

#define ashStopNrTimer

()

Stops the Not Ready timer.

ashNrTimerIsNotRunning#

#define ashNrTimerIsNotRunning

()

Indicates whether or not ashNrTimer is currently running.

ASH_VERSION#

#define ASH_VERSION

2

protocol version

ASH_FLAG#

#define ASH_FLAG

0x7E

frame delimiter

ASH_ESC#

#define ASH_ESC

0x7D

byte stuffing escape byte

ASH_XON#

#define ASH_XON

0x11

flow control byte - means resume transmission

ASH_XOFF#

#define ASH_XOFF

0x13

flow control byte - means suspend transmission

ASH_SUB#

#define ASH_SUB

0x18

replaces bytes w framing, overrun or overflow errors

ASH_CAN#

#define ASH_CAN

0x1A

frame cancel byte

ASH_WAKE#

#define ASH_WAKE

0xFF

wake signal byte (also means NCP data pending)

ASH_FLIP#

#define ASH_FLIP

0x20

XOR mask used in byte stuffing.

ASH_MIN_DATA_FIELD_LEN#

#define ASH_MIN_DATA_FIELD_LEN

EZSP_MIN_FRAME_LENGTH

ash min data field len

ASH_MAX_DATA_FIELD_LEN#

#define ASH_MAX_DATA_FIELD_LEN

EZSP_MAX_FRAME_LENGTH

ash max data field len

ASH_MIN_DATA_FRAME_LEN#

#define ASH_MIN_DATA_FRAME_LEN

(ASH_MIN_DATA_FIELD_LEN + 1)

with control

ASH_MIN_FRAME_LEN#

#define ASH_MIN_FRAME_LEN

1

control plus data field, but not CRC

ASH_MAX_FRAME_LEN#

#define ASH_MAX_FRAME_LEN

(ASH_MAX_DATA_FIELD_LEN + 1)

ash max frame len

ASH_CRC_LEN#

#define ASH_CRC_LEN

2

ash crc len

ASH_MIN_FRAME_WITH_CRC_LEN#

#define ASH_MIN_FRAME_WITH_CRC_LEN

(ASH_MIN_FRAME_LEN + ASH_CRC_LEN)

ash min frame with crc len

ASH_MAX_FRAME_WITH_CRC_LEN#

#define ASH_MAX_FRAME_WITH_CRC_LEN

(ASH_MAX_FRAME_LEN + ASH_CRC_LEN)

ash max frame with crc len

ASH_NCP_SHFRAME_RX_LEN#

#define ASH_NCP_SHFRAME_RX_LEN

2

longest non-data frame received

ASH_NCP_SHFRAME_TX_LEN#

#define ASH_NCP_SHFRAME_TX_LEN

3

longest non-data frame sent

ASH_HOST_SHFRAME_RX_LEN#

#define ASH_HOST_SHFRAME_RX_LEN

3

longest non-data frame received

ASH_HOST_SHFRAME_TX_LEN#

#define ASH_HOST_SHFRAME_TX_LEN

2

longest non-data frame sent

ASH_DFRAME_MASK#

#define ASH_DFRAME_MASK

0x80

ash dframe mask

ASH_CONTROL_DATA#

#define ASH_CONTROL_DATA

0x00

ash control data

ASH_SHFRAME_MASK#

#define ASH_SHFRAME_MASK

0xE0

ash shframe mask

ASH_CONTROL_ACK#

#define ASH_CONTROL_ACK

0x80

ash control ack

ASH_CONTROL_NAK#

#define ASH_CONTROL_NAK

0xA0

ash control nak

ASH_CONTROL_RST#

#define ASH_CONTROL_RST

0xC0

ash control rst

ASH_CONTROL_RSTACK#

#define ASH_CONTROL_RSTACK

0xC1

ash control rstack

ASH_CONTROL_ERROR#

#define ASH_CONTROL_ERROR

0xC2

ash control error

ASH_ACKNUM_MASK#

#define ASH_ACKNUM_MASK

0x07

acknowledge frame number

ASH_ACKNUM_BIT#

#define ASH_ACKNUM_BIT

0

ash acknum bit

ASH_RFLAG_MASK#

#define ASH_RFLAG_MASK

0x08

retransmitted frame flag

ASH_RFLAG_BIT#

#define ASH_RFLAG_BIT

3

ash rflag bit

ASH_NFLAG_MASK#

#define ASH_NFLAG_MASK

0x08

receiver not ready flag

ASH_NFLAG_BIT#

#define ASH_NFLAG_BIT

3

ash nflag bit

ASH_PFLAG_MASK#

#define ASH_PFLAG_MASK

0x10

flag reserved for future use

ASH_PFLAG_BIT#

#define ASH_PFLAG_BIT

4

ash pflag bit

ASH_FRMNUM_MASK#

#define ASH_FRMNUM_MASK

0x70

DATA frame number.

ASH_FRMNUM_BIT#

#define ASH_FRMNUM_BIT

4

ash frmnum bit

ASH_GET_RFLAG#

#define ASH_GET_RFLAG

(ctl)

ash get rflag(ctl)

ASH_GET_NFLAG#

#define ASH_GET_NFLAG

(ctl)

ash get nflag(ctl)

ASH_GET_FRMNUM#

#define ASH_GET_FRMNUM

(ctl)

ash get frmnum(ctl)

ASH_GET_ACKNUM#

#define ASH_GET_ACKNUM

(ctl)

ash get acknum(ctl)

ASH_FRAME_LEN_DATA_MIN#

#define ASH_FRAME_LEN_DATA_MIN

(ASH_MIN_DATA_FIELD_LEN + 1)

ash frame len data min

ASH_FRAME_LEN_ACK#

#define ASH_FRAME_LEN_ACK

1

control

ASH_FRAME_LEN_NAK#

#define ASH_FRAME_LEN_NAK

1

control

ASH_FRAME_LEN_RST#

#define ASH_FRAME_LEN_RST

1

control

ASH_FRAME_LEN_RSTACK#

#define ASH_FRAME_LEN_RSTACK

3

control, version, reset reason

ASH_FRAME_LEN_ERROR#

#define ASH_FRAME_LEN_ERROR

3

control, version, error

MOD8#

#define MOD8

(n)

mask to frame number modulus

INC8#

#define INC8

(n)

increment in frame number modulus

WITHIN_RANGE#

#define WITHIN_RANGE

(lo, n, hi)

within range lo and hi