MC68000 MOTOROLA [Motorola, Inc], MC68000 Datasheet - Page 358
MC68000
Manufacturer Part Number
MC68000
Description
Manufacturer
MOTOROLA [Motorola, Inc]
Datasheet
1.MC68000.pdf
(480 pages)
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
MC68000-10/BZAJC
Manufacturer:
MOT
Quantity:
26
Company:
Part Number:
MC68000-8BXAJ
Manufacturer:
MOT
Quantity:
9
Company:
Part Number:
MC680008FN8
Manufacturer:
FREESCALE
Quantity:
8 831
Company:
Part Number:
MC68000FN10
Manufacturer:
MOT
Quantity:
5 510
Part Number:
MC68000FN10
Manufacturer:
MOTOROLA/摩托罗拉
Quantity:
20 000
Company:
Part Number:
MC68000FN12
Manufacturer:
MOT
Quantity:
5 510
Part Number:
MC68000L8
Manufacturer:
MOTOROLA/摩托罗拉
Quantity:
20 000
Part Number:
MC68000P10
Manufacturer:
MOT
Quantity:
20 000
- Current page: 358 of 480
- Download datasheet (2Mb)
MC68302 Applications
The TBD# and RBD# are pointers used by the SCC to show which BD the SCC is currently
using (or which one it will be using next). TBD# and RBD# always sequence around the
queue of BDs in a circular fashion and are initialized to the first BD as shown.
D.3.2 MC68302 Buffer Processing
The communications processor (CP) processes the transmit BDs in a straightforward fash-
ion. Once the transmit side of an SCC is enabled, the CP starts with the first BD in that SCC's
transmit BD table, periodically checking the ready bit to see if that BD is ready. Once that
BD is ready, the CP will process that BD, reading a word at a time from its associated buffer,
doing certain required protocol processing on the data, and moving resultant data to the
SCC transmit FIFO. When the first buffer has been processed, the CP moves on to the next
BD, again waiting for that BD's ready bit to be set. Thus, the CP does no look-ahead BD
processing, nor does it skip over BDs that are not ready. When the CP sees the wrap bit set
in a BD, it goes back to the beginning of the BD table after processing of this BD is complete.
After using a BD, the CP sets its ready bit to not-ready; thus, the CP will not use a BD twice.
The BD must be confirmed by the M68000 core before being used again.
The CP uses the receive BDs in a similar fashion. Once the receive side of an SCC is en-
abled, the CP starts with the first BD in that SCC's receive BD table. Once data arrives from
the serial line into the SCC, the CP performs certain required protocol processing on the
data and moves the resultant data (either by bytes or by words, depending on the protocol)
to the buffer pointed to by the first BD. Use of a BD is complete when there is no more room
D-8
Figure D-4. Transmit and Receive BD Tables
TBD#
TRANSMIT BD TABLE
R = 0
R = 0
R = 0
R = 0
R = 0
R = 0
R = 0
R = 0
MC68302 USER’S MANUAL
7
5
6
3
4
0
1
2
RBD#
RECEIVE BD TABLE
E = 1
E = 1
E = 1
E = 1
E = 1
E = 1
E = 1
E = 1
3
4
5
6
7
0
1
2
MOTOROLA
Related parts for MC68000
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
Part Number:
Description:
Motorola, Inc [VOLTAGE REGULATOR]
Manufacturer:
Motorola
Datasheet:
Part Number:
Description:
6367254 MOTOROLA SC (XSTRS/R F)
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
MC1494LMotorola, Inc [MONOLITHIC FOUR-QUADRANT MULTIPLIER]
Manufacturer:
Motorola
Datasheet:
Part Number:
Description:
MC1466LMotorola, Inc [PRECISION WIDE RANGE VOLTAGE AND CURRENT REGULATOR]
Manufacturer:
Motorola
Datasheet:
Part Number:
Description:
MC145532DWMotorola, Inc [ADPCM Transcoder]
Manufacturer:
Motorola
Datasheet:
Part Number:
Description:
Silicon Controlled Rectifiers
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
RF Power Field Effect Transistors N-Channel Enhancement-Mode Lateral MOSFETs
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
RF POWER FIELD EFFECT TRANSISTORS
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
LATERAL N-CHANNEL BROADBAND RF POWER MOSFETs
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
RF POWER FIELD EFFECT TRANSISTOR
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
RF LOW POWER TRANSISTOR NPN SILICON
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
PLASTIC SURFACE MOUNT ZENER DIODES 1.5 WATTS 3.3-68 VOLTS
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
OVERVOLTAGE TRANSIENT SUPPRESSOR
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
TMOS POWER FET 15 AMPERES 60 VOLTS
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
TMOS POWER FET LOGIC LEVEL 19 AMPERES 30 VOLTS RDS(on) = 0.099 OHM
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet: