參數(shù)資料
型號(hào): CD1284
廠商: Intel Corp.
英文描述: IEEE 1284-Compatible Parallel Interface Controller with Two High-Speed Asynchronous Serial Ports
中文描述: 符合IEEE 1284兼容并行接口控制器兩個(gè)高速異步串行端口
文件頁數(shù): 93/176頁
文件大?。?/td> 2255K
代理商: CD1284
IEEE 1284-Compatible Parallel Interface Controller
CD1284
Datasheet
93
6.2.2
Global Function Initialization
Once chip reset has been completed, the next step is to set the Global Operating mode and timer
prescale. All other initialization occurs at the channel level.
Set the Prescaler Period Register (PPR)
The PPR sets the master time
tick
for the CD1284. It is a binary value that sets a constant by
which the system clock is divided (after a fixed prescale of 512) to produce the internal clock for
the on-chip timers (This does not include baud rate generators). This clock is used for receiver
FIFO time-out generation and delay timing for the insert delay command in the embedded transmit
command set. For example, to generate a timer clock of 1 ms, the value is computed as:
The value 49 is loaded into the PPR. This value, selects an approximate 1-kHz clock as the source
for the RTPR (Receiver Time-out Period registers) of each channel. Those registers are loaded with
an appropriate value divisor that generate the desired character time-out periods. This value, 49, is
the recommended minimum value that is placed in the PPR for a clock frequency of 25 MHz.
Values that generate a time period of less than 1 ms adversely affect the performance of the MPU,
and thus, overall serial data performance.
6.2.3
Serial Channel Initialization
At this point, the basic operation of the CD1284 serial channels are set up. The internal register
states are cleared and basic timer operations are initialized. The next step is programming the
operating modes of each channel. This includes setting the values for the interrupt vectors, the
receive and transmit baud rates, number of bits per character, number of stop bits, parity, special
characters, if any, and so on. Each channel can have a completely unique set of operating
characteristics or they can all be the same.
Serial channel initialization is application-dependent. The operating modes of one channel have no
effect on the operation of others.
The following code, is a typical initialization sequence for setting up a single serial channel:
9600 baud, send and receive
8 bits per character, 1 stop bit,No parity
Automatic In-Band (Xon/Xoff) flow control
Transparent flow control
Special character detect enabled
Eight character receive FIFO threshold
Receiver and transmitter enabled for interrupt operation
Enable ISTRIP on incoming characters
A clear way of showing this initialization sequence is by a
C
program fragment; the code shown
below, is compatible with Borland
Turbo C
:
/* Init channel. Channel number is included in call. Register names and addresses
are defined in the header file (not shown). This routine does not include parallel
channel initialization. */
init_channel(chan)
char
chan
{
MHz
512
25
1
ms
×
48.828
=
相關(guān)PDF資料
PDF描述
CD13002 NPN SILICON PLANAR EPITAXIAL, HIGH VOLTAGE FAST SWITCHING POWER TRANSISTOR
CD14538 CMOS DUAL PRECISION MONOSTABLE MULTIVIBRATOR
CD14538BMS CMOS Dual Precision Monostable Multivibrator
CD15B-15MB CD105B
CD105B CD105B
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
CD-12AFFM-QL8D01 功能描述:MIDDLE 制造商:amphenol ltw 系列:* 零件狀態(tài):在售 標(biāo)準(zhǔn)包裝:10
CD-12AFFM-QR8D01 功能描述:MIDDLE 制造商:amphenol ltw 系列:* 零件狀態(tài):在售 標(biāo)準(zhǔn)包裝:10
CD-12AMMM-QL8D01 功能描述:MIDDLE 制造商:amphenol ltw 系列:* 零件狀態(tài):在售 標(biāo)準(zhǔn)包裝:10
CD-12BFFA-LL7001 功能描述:MIDDLE 制造商:amphenol ltw 系列:* 零件狀態(tài):在售 標(biāo)準(zhǔn)包裝:10
CD-12BFFA-QL8SP0 功能描述:CONN PLUG FMALE 12POS CRIMP 制造商:amphenol ltw 系列:X-Lok 包裝:散裝 零件狀態(tài):在售 連接器類型:插頭,母型插口 針腳數(shù):12(數(shù)據(jù)) 外殼尺寸 - 插件:C 外殼尺寸,MIL:- 安裝類型:自由懸掛 端接:壓接 緊固類型:推挽式 朝向:帶標(biāo)記 侵入防護(hù):IP68 - 防塵,防水 外殼材料,鍍層:聚酰胺(PA),尼龍,玻璃纖維增強(qiáng)型 觸頭鍍層:金 特性:后殼,應(yīng)力消除 電壓 - 額定:- 額定電流:5A 觸頭鍍層厚度:- 工作溫度:-20°C ~ 80°C 標(biāo)準(zhǔn)包裝:1