MC68HC901P MOTOROLA [Motorola, Inc], MC68HC901P Datasheet - Page 45
MC68HC901P
Manufacturer Part Number
MC68HC901P
Description
Multi-Function Peripheral
Manufacturer
MOTOROLA [Motorola, Inc]
Datasheet
1.MC68HC901P.pdf
(73 pages)
- Current page: 45 of 73
- Download datasheet (264Kb)
Universal Synchronous/Asynchronous Receiver-Transmitter
7.1.1 Asynchronous Format
Variable character length and start/stop bit configurations are available under software
control for asynchronous operation. The user can choose a character length from five to
eight bits and a stop bit length of one, one and one-half, or two bits. The user can also select
odd, even, or no parity.
In the asynchronous format, start bit detection is always enabled. New data is not shifted
into the receive shift register until a zero bit is received. When the divide-by-16 clock mode
is selected, the false start bit logic is also active. Any transition must be stable for three
positive receive clock edges to be considered valid. For a start bit to be good, a valid zero-
to-one transition must not occur for eight positive receiver clock transitions after the initial
one-to-zero transition. After a valid start bit has been detected, the data is checked
continuously for valid transitions. When a valid transition is detected, an internal counter is
forced to state zero, and no further transition checking is initiated until state four. At state
eight, the “previous state” of the transition checking logic is clocked into the receiver. As a
result of this re-synchronization logic, it is possible to run with asynchronous clocks without
start and stop bits if there are sufficient valid transitions in the data streams.
7.1.2 Synchronous Format
When the synchronous character format is selected, the 8-bit synchronous character loaded
into the synchronous character register (SCR) is compared to received serial data until a
match is found. Once synchronization is established, incoming data is clocked into the
receiver. The synchronous word will be continuously transmitted during an underrun
condition. All synchronous characters can be optionally stripped from the receive buffer (i.e.,
taken out of the data stream and thrown away) by clearing the appropriate bit in the receive
status register (RSR).
D7-D0 — Data
The synchronous character should be written after the character length is selected, since
unused bits in the synchronous character register are zeroed out. When parity is enabled,
synchronous word length is the character length plus one. The MFP will compute and
append the parity bit for the synchronous character.
7-2
SCR REGISTER
RESET
FIELD
ADDR
BIT
0 = Cleared.
1 = Set.
D7
7
0
D6
6
0
MC68HC901 USER’S MANUAL
D5
5
0
D4
4
0
$27
D3
3
0
D2
2
0
D1
1
0
MOTOROLA
D0
0
0
Related parts for MC68HC901P
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: