1. . l- Ns : Ns = Vs. 1 Vs:= Vs+1.
2. . 2, . l-, Ns- Vr. , , Vr:= Vr+1.
, ,
S- RNR Mr = Vr. -
, , l-
l-, S- RR REJ,
, 1.
, . , l-, Nr:= Vr. , S- RR Nr = Vr.
Ns <> Vr, l-, S- REJ Nr = Vr. l-, I- Ns = Vr.
, 2, , 1 2 , - 2, - 1.
3. .
l-, S- ( RNR REJ).
1
. Nr-1- REJ,
Ι- Ι- Nr Ns. S- U-, 1-. , S- RR, RNR REJ = 1 1. .
4. . S-
F = 1 S- RNR, F:= 1,
, , S- RR, REJ
F = 1, . ,
Ι-.
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5. . 1,
, . -
.
. REJ- P/F-. , , = 1, F = 1. = 1 , F = 1. , = 1 , 1, , REJ-, .
S- SREJ, , l-. SREJ , l- Ns-1 = Vr, Mr = Vr, . l- Ns < Nr.
SREJ , - SREJ-, , 1- , SREJ-. SREJ- Ι-, SREJ- . SREJ- , SREJ- Ι- Nr, P/F = 1 Ns < Mr, a SREJ- P/F = 0 .
HDLC-. . HDLC - 7- OSI. , , , (SDLC, SS#7, LAPD, LAPB) HDLC- . HDLC- . 5.112.
, OSI . 01111110 (07), , . bit-stuffing, .
. . HDLC- 8- 16- .
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(8- 16-) ( l-, S-, U-) .
3- () OSI. . , , HDLC-, 8 128. .
16-, 32- . 16- CRC. LSB, CRC MSB. .
SCC- HDLC- GSMR MODE. HDLC- PSMR (. 5.113). HDLC- ISDN- (IDL, GCI ) - D-, SCC- NMSI-. - HDLC- D- ISDN-.
860 HDLC bus. BUS PSMR (. 5.113) HDLC- (0 - HDLC-, 1 - HDLC bus).
HDLC-, HDLC bus, BRM. BRM = 0, , = 0 = 1 , . BRM = 1 . , , 1 ,
= 0, . , , .
HDLC- . , , . NMSI- , BRG, . HDLC- , SCC-.
HDLC- BD . , . BD F = 1 (First), - L = 1 (Last). , . (overrun) (underrun) , , .
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HDLC- STOP TRANSMIT, GRACEFUL STOP TRANSMIT, RESTART TRANSMIT, INIT TX PARAMETERS ENTER HUNT MODE, INIT RX PARAMETERS.
. DRT:= 1. , RTS = 0. , ( multidrop), , .
860 . 5.77.
5.77
HDLC- 860
, | |||
SCC base+30 | - | ||
SCC base+34 | C_MASK | CRC | |
SCC base+38 | C_PRES | CRC | |
SCC base+3C | DISFC | ||
SCC base+3E | CRCEC | CRC | |
SCC base+40 | ABTSC | ABORT- | |
SCC base+42 | NMARC | ||
SCC base+44 | RETRC | ||
SCC base+46 | MFLR | ||
SCC base+48 | MAX_cnt | ||
SCC base+4A | RFTHR | ||
SCC base+4C | RFCNT | ||
SCC base+4E | HMASK | ||
SCC base+50 | HADDR1 | , | |
SCC base+52 | HADDR2 | , | |
SCC base+54 | HADDR3 | , | |
SCC base+56 | HADDR4 | , | |
SCC base+58 | |||
SCC base+5A | _ MB | ||
. , MAX_cnt, RFCNT, _, | |||
_ HDLC-. |
. HDLC- 860 196 , , , , .
. , , , . HDLC- HADDR1-HADDR4 HMASK. , , , . , HADDR . , . , 16 , HMASK = 0xFFFF, , HMASK = 0x00FF. . , HADDRi . HDLC- , HADDRi (broadcast) 0xFFFF.
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, , NMARC HDLC-.
, , , . HDLC- BD . BD E = 1, SDMA. := 0 , BD I = 1, , . , , BD , . , .
HDLC- ( ). MFLR . , BD LG:= 1. , , , BD . MAX_CNT . MAX_CNT:= MFLR. , .
, . , , , BD CR:= 1 , , RXF- . CRC CRCEC , ( ).
, BD , := 0. , , , , , .
HDLC- BD , . HDLC- , RFTHR- . RECNT. , , . , .
HDLC- FIFO. FIFO SDMA- RISC- , 8-32 . RISC- FIFO FIFO , - overrun. , . , OV:= 1 , , . , FIFO RISC- , , . ( ).
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, , , RISC- , DISFC .
. ( = 1), , , BD (CD:= 1) , , RXF . , , (hunt-).
HDLC- 8 . , 8, , , NO:= 1 BD , , RXF-- . .
, ABORT-. , BD := 1 , , RXF . ABORT- ABTSC , . , CRC 8 .
. HDLC- ( 01111110). FSE = 1 RTSM GSMR , [NOF+1] . RTSM = 0, IDLE-.
BD. , SDMA- FIFO . , FIFO . , , NOF3 NOF0. 0000, .
, BD L = 1 (Last), . CRC = 00, 16- . CRC = 10, 32- . C_MASK , 1 i- X i. 16+12+5+1 OxOOOFOB8, 32+ 26+23+22+ 16+12 + + 11+10++7+5+4+2+1+1 - 0xDEBB20E3. HDLC- C_PRES CRC. 16- 0x0000FFFF, 32- -0xFFFFFFFF. , CRC, .
. TCRC RCRC - .
32- , HDLC Ethernet. 32- CRC, , 16- 32-.
, RISC- R:= 0 BD, . , BD. , , , R = 1.
I = 1 (Interrupt), . , .
, STOP TRANSMIT. , , , . GRACEFUL STOP TRANSMIT. STOP TRANSMIT, HDLC- IDLE, RESTART TRANSMIT .
, HDLC- , , BD , , - SCC-. RESTART TRANSMIT, .
. underrun , , , . UN:= 1 BD.
HDLC- = 0. ( = 1), CTS- ( ). := 1 BD. RTE = 0 . CTS RTE = 1, HDLC- RETRC . RTE = 0, , . ,
36 SCC1 20 - SCC-
860.