參數(shù)資料
型號: 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高速異步串行端口
文件頁數(shù): 57/176頁
文件大小: 2255K
代理商: CD1284
IEEE 1284-Compatible Parallel Interface Controller
CD1284
Datasheet
57
If enabled in SCD12 and a character matching the contents of SCHR2 is received (the XOFF
character), the CD1284 checks that automatic transmit in-band flow control is enabled in COR2[6].
If this function is enabled, the CD1284 stops transmission after the current transmitting character
and the character in the Transmitter Holding register, if any, are sent. If enabled, the CD1284 also
attempts to match against errored characters. This function is enabled by the CMOE bit (COR5[5]).
COR2[7] enables IXM (Implied XON mode), which determines the character that restarts
transmission after a stop by automatic flow control. If IXM (COR2[7]) is
0
, only a programmed
XON character (SCHR1) can restart the transmitter; all other characters are received and placed in
the FIFO. If IXM is reset, any character received restarts data transmission. TxIBE (COR2[6])
must be set to active automatic flow control, otherwise IXM (COR2[7]) has no effect.
As with receiver flow control, the CPU can determine the current state of the transmitter through
TXFloff and TxFlon (CCSR[2:1]). When automatic in-band flow control is enabled and the
CD1284 receives an XOFF character, TxFloff is set. When an XON character is received, TxFlon
is set. Once transmission resumes, TxFlon is cleared. The encoding for TxFloff and TxFlon is
shown in
Table 16
.
TxFloff and TxFlon are cleared whenever the transmitter is disabled or enabled, regardless of the
state of flow control when the disable/enable occurred. This feature can force transmission to
resume regardless of remote-initiated flow control.
One final aspect of automatic in-band flow control is FCT (Flow Control Transparency). FCT is
enabled/disabled in COR3[5] and determines if remote-initiated flow control is transparent to the
CPU. If FCT is not set, in addition to stopping transmission when an XOFF character is received,
the CD1284 places the received XOFF character in the receive FIFO and informs the CPU with a
receive exception service request. When the XON character is received, it is also sent to the CPU
by an exception service request, then restarts data transmission.
If FCT is enabled, received flow control characters control transmission, but are discarded instead
of being placed in the FIFO. If the CPU does not require to know when its transmit data has been
stopped, this bit can be set to reduce the number of service requests that must be handled.
Table 17
summarizes the control bits in the CORs that enable the various modes of in-band flow
control.
Table 16. CCSR[2:1] Encoding
TxFloff
TxFlon
Encoded Status
0
0
Transmission resumes, transmitter is
enabled/disabled, or the transmitter is
in the default reset state.
0
1
XON was received, but transmission
has not restarted.
1
0
XOFF was received, transmission has
stopped.
1
1
Not used.
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 標準包裝:10
CD-12AFFM-QR8D01 功能描述:MIDDLE 制造商:amphenol ltw 系列:* 零件狀態(tài):在售 標準包裝:10
CD-12AMMM-QL8D01 功能描述:MIDDLE 制造商:amphenol ltw 系列:* 零件狀態(tài):在售 標準包裝:10
CD-12BFFA-LL7001 功能描述:MIDDLE 制造商:amphenol ltw 系列:* 零件狀態(tài):在售 標準包裝: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:帶標記 侵入防護:IP68 - 防塵,防水 外殼材料,鍍層:聚酰胺(PA),尼龍,玻璃纖維增強型 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 標準包裝:1