Motor de Búsqueda de Datasheet de Componentes Electrónicos
  Spanish  ▼
ALLDATASHEET.ES

X  

CDP1854ACEX Datasheet(PDF) 8 Page - Intersil Corporation

No. de pieza CDP1854ACEX
Descripción Electrónicos  Programmable Universal Asynchronous Receiver/Transmitter (UART)
Download  21 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Fabricante Electrónico  INTERSIL [Intersil Corporation]
Página de inicio  http://www.intersil.com/cda/home
Logo INTERSIL - Intersil Corporation

CDP1854ACEX Datasheet(HTML) 8 Page - Intersil Corporation

Back Button CDP1854ACEX Datasheet HTML 4Page - Intersil Corporation CDP1854ACEX Datasheet HTML 5Page - Intersil Corporation CDP1854ACEX Datasheet HTML 6Page - Intersil Corporation CDP1854ACEX Datasheet HTML 7Page - Intersil Corporation CDP1854ACEX Datasheet HTML 8Page - Intersil Corporation CDP1854ACEX Datasheet HTML 9Page - Intersil Corporation CDP1854ACEX Datasheet HTML 10Page - Intersil Corporation CDP1854ACEX Datasheet HTML 11Page - Intersil Corporation CDP1854ACEX Datasheet HTML 12Page - Intersil Corporation Next Button
Zoom Inzoom in Zoom Outzoom out
 8 / 21 page
background image
5-49
Description of Mode 1 Operation
CDP1800-Series Microprocessor
Compatible (Mode Input = VDD)
Initialization and Controls
In the CDP1800-series microprocessor compatible mode,
the CDP1854A is configured to receive commands and send
status via the microprocessor data bus. The register
connected to the transmitter bus or the receiver bus is
determined by the RD/WR and RSEL inputs as follows:
In
this
mode
the
CDP1854A
is
compatible
with
a
bidirectional bus system. The receiver and transmitter buses
are connected to the bus. CDP1800-series microprocessor
I/O control output signals can be connected directly to the
CDP1854A inputs as shown in Figure 2. The CLEAR input is
pulsed, resetting the Control, Status, and Receiver Holding
Registers and setting SERIAL DATA OUT (SDO) high. The
Control Register is loaded from the Transmitter Bus in order
to determine the operating configuration for the UART. Data
is transferred from the Transmitter Bus inputs to the Control
Register during TPB when the UART is selected (CS1
• CS2
• CS3 = 1) and the Control Register is designated (RSEL =
H, RD/WR = L). The CDP1854A also has a Status Register
which can be read onto the Receiver Bus (R BUS 0 - R BUS
7) in order to determine the status of the UART. Some of
these status bits are also available at separate terminals as
indicated in Table 2.
Transmitter Operation
Before beginning to transmit, the TRANSMlT REQUEST
(TR) bit in the Control Register (see bit assignment, Table 4)
is set. Loading the Control Register with TR = 1 (bit 7 = high)
inhibits changing the other control bits. Therefore two loads
are required: one to format the UART, the second to set TR.
When TR has been set, a TRANSMlTTER HOLDING REG-
ISTER EMPTY (THRE) interrupt will occur, signalling the
microprocessor that the Transmitter Holding Register is
empty and may be loaded. Setting TR also causes assertion
of a low-level on the REQUEST TO SEND (RTS) output to
the peripheral. It is not necessary to set TR for proper opera-
tion for the UART. If desired, it can be used to enable THRE
interrupts and to generate the RTS signal. The Transmitter
Holding Register is loaded from the bus by TPB during exe-
cution of an output instruction. The CDP1854A is selected
by CS1
• CS2 • CS3 = 1, and the Holding Register is
selected by RSEL = L and RD/WR = L. When the CLEAR
TO SEND (CTS) input, which can be connected to a periph-
eral device output, goes low, the Transmitter Shift Register
will be loaded from the Transmitter Holding Register and
data transmission will begin. If CTS is always low, the Trans-
mitter Shift Register will be loaded on the first high-to-low
edge of the clock which occurs at least 1/2 clock period after
the trailing edge of TPB and transmission of a start bit will
occur 1/2 clock period later (see Figure 3). Parity (if pro-
grammed) and stop bit(s) will be transmitted following the
last data bit. If the word length selected is less than 8 bits,
the most significant unused bits in the transmitter shift regis-
ter will not be transmitted.
One transmitter clock period after the Transmitter Shift Reg-
ister is loaded from the Transmitter Holding Register, the
THRE signal will go low and an interrupt will occur (INT goes
low). The next character to be transmitted can then be
loaded into the Transmitter Holding Register for transmission
with its start bit immediately following the last stop bit of the
previous character. This cycle can be repeated until the last
character is transmitted, at which time a final THRE
• TSRE
interrupt will occur. This interrupt signals the microprocessor
that TR can be turned off. This is done by reloading the orig-
inal control byte in the Control Register with the TR bit 0,
thus terminating the REQUEST TO SEND (RTS) signal.
SERIAL DATA OUT (SDO) can be held low by setting the
BREAK bit in the Control Register (see Table 4). SDO is held
low until the BREAK bit is reset.
Receiver Operation
The receive operation begins when a start bit is detected at
the SERlAL DATA IN (SDl) input. After detection of the first
high-to-low transition on the SDl line, a valid start bit is
verified by checking for a low-level input 7-1/2 receiver clock
periods later. When a valid start bit has been verified, the fol-
lowing data bits, parity bit (if programmed) and stop bit(s) are
shifted into the Receiver Shift Register by clock pulse 7-1/2
TABLE 3. REGISTER SELECTION SUMMARY
RSEL
RD/WR
FUNCTION
Low
Low
Load Transmitter Holding Register from
Transmitter Bus
Low
High
Read Receiver Holding Register from
Receiver Bus
High
Low
Load Control Register from Transmitter
Bus
High
High
Read Status Register from Receiver Bus
FIGURE 2. RECOMMENDED CDP1800-SERIES CONNECTION,
MODE 1 (NON-INTERRUPT DRIVEN SYSTEM)
N0
N1
N2
MRD
TPB
INT
EFX
EFX
EFX
EFX
BUS
CLEAR
(8)
CPU
RSEL
CS1
CS2
RD/WR
TPB
INT
THRE
DA
T BUS
CS3
T CLOCK R CLOCK
RTS
CTS
ES
PSI
SDO
SDI
MODE
CLEAR
VDD
FE
PE/OE
R BUS
VSS
VDD
UART
CDP1854A
CDP1854A, CDP1854AC


Número de pieza similar - CDP1854ACEX

Fabricante ElectrónicoNo. de piezaDatasheetDescripción Electrónicos
logo
Intersil Corporation
CDP1854AC INTERSIL-CDP1854AC Datasheet
126Kb / 12P
   High Reliability CMOS Programmable Universal Asynchronous Receiver/Transmitter (UART)
CDP1854AC3 INTERSIL-CDP1854AC3 Datasheet
126Kb / 12P
   High Reliability CMOS Programmable Universal Asynchronous Receiver/Transmitter (UART)
CDP1854ACD3 INTERSIL-CDP1854ACD3 Datasheet
126Kb / 12P
   High Reliability CMOS Programmable Universal Asynchronous Receiver/Transmitter (UART)
More results

Descripción similar - CDP1854ACEX

Fabricante ElectrónicoNo. de piezaDatasheetDescripción Electrónicos
logo
Intersil Corporation
IM7332 INTERSIL-IM7332 Datasheet
1Mb / 36P
   Universal Asynchronous Receiver Transmitter(UART)
logo
A1 PROs co., Ltd.
EI16C450 A1PROS-EI16C450 Datasheet
1Mb / 1P
   Universal Asynchronous Receiver Transmitter(UART)
06/15/99
logo
Exar Corporation
ST16C450 EXAR-ST16C450 Datasheet
182Kb / 28P
   UNIVERSAL ASYNCHRONOUS RECEIVER/TRANSMITTER (UART)
logo
List of Unclassifed Man...
COM8017 ETC-COM8017 Datasheet
553Kb / 8P
   UNIVERSAL ASYNCHRONOUS RECEIVER/TRANSMITTER UART
logo
NXP Semiconductors
SCC2691 PHILIPS-SCC2691 Datasheet
168Kb / 24P
   Universal asynchronous receiver/transmitter UART
1998 Sep 04
logo
Exar Corporation
ST16C454 EXAR-ST16C454 Datasheet
378Kb / 30P
   QUAD UNIVERSAL ASYNCHRONOUS RECEIVER/TRANSMITTER (UART)
logo
Intersil Corporation
HD-6402 INTERSIL-HD-6402 Datasheet
154Kb / 7P
   CMOS Universal Asynchronous Receiver Transmitter (UART)
CDP1854A INTERSIL-CDP1854A_1 Datasheet
126Kb / 12P
   High Reliability CMOS Programmable Universal Asynchronous Receiver/Transmitter (UART)
logo
Harris Corporation
HD6402 HARRIS-HD6402 Datasheet
100Kb / 6P
   CMOS Universal Asynchronous Receiver Transmitter (UART)
logo
Intersil Corporation
HD-6402 INTERSIL-HD-6402 Datasheet
92Kb / 6P
   CMOS Universal Asynchronous Receiver Transmitter (UART)
March 1997
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21


Datasheet Descarga

Go To PDF Page


Enlace URL




Política de Privacidad
ALLDATASHEET.ES
¿ALLDATASHEET es útil para Ud.?  [ DONATE ] 

Todo acerca de Alldatasheet   |   Publicidad   |   Contáctenos   |   Política de Privacidad   |   Intercambio de Enlaces   |   Lista de Fabricantes
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com