參數(shù)資料
型號: DS21FT42
廠商: DALLAS SEMICONDUCTOR
元件分類: Digital Transmission Controller
英文描述: DATACOM, FRAMER, PBGA300
封裝: 27 X 27 MM, BGA-300
文件頁數(shù): 41/115頁
文件大?。?/td> 534K
代理商: DS21FT42
DS21FF42/DS21FT42
31 of 115
NOTES:
1. Test Registers 1 and 2 are used only by the factory; these registers must be cleared (set to all zeros) on
power– up initialization to insure proper operation.
2. Register banks AxH, BxH, CxH, DxH, ExH, and FxH are not accessible.
9. PARALLEL PORT
The DS21Q42 is controlled via either a nonmultiplexed (MUX = 0) or a multiplexed (MUX = 1) bus by
an external microcontroller or microprocessor. The DS21Q42 can operate with either Intel or Motorola
bus timing configurations. If the BTS pin is tied low, Intel timing will be selected; if tied high, Motorola
timing will be selected. All Motorola bus signals are listed in parenthesis (). See the timing diagrams in
the A.C. Electrical Characteristics in Section 25 for more details.
10.
CONTROL, ID AND TEST REGISTERS
The operation of each framer within the DS21Q42 is configured via a set of eleven control registers.
Typically, the control registers are only accessed when the system is first powered up. Once a channel in
the DS21Q42 has been initialized, the control registers will only need to be accessed when there is a
change in the system configuration. There are two Receive Control Register (RCR1 and RCR2), two
Transmit Control Registers (TCR1 and TCR2), and seven Common Control Registers (CCR1 to CCR7).
Each of the eleven registers are described in this section. There is a device Identification Register (IDR)
at address 0Fh. The MSB of this read–only register is fixed to a zero indicating that the DS21Q42 is
present. The E1 pin–for–pin compatible version of the DS21Q42 is the DS21Q44 and it also has an ID
register at address 0Fh and the user can read the MSB to determine which chip is present since in the
DS21Q42 the MSB will be set to a zero and in the DS21Q44 it will be set to a one. The lower four bits
of the IDR are used to display the die revision of the chip.
POWER–UP SEQUENCE
The DS21Q42 does not automatically clear its register space on power–up. After the supplies are stable,
each of the four framer’s register space should be configured for operation by writing to all of the internal
registers. This includes setting the Test and all unused registers to 00Hex.
This can be accomplished using a two-pass approach on each framer within the DS21Q42.
1. Clear framer’s register space by writing 00H to the addresses 00H through 09FH.
2. Program required registers to achieve desired operating mode.
NOTE:
When emulating the DS21Q41 feature set (FMS = 1), the full address space (00H through 09FH) must be
initialized. DS21Q41 emulation requires address pin A7 to be used. FMS is tied to ground for the
DS21FF42/DS21FT42.
Finally, after the TSYSCLK and RSYSCLK inputs are stable, the ESR bit should be toggled from a zero
to a one (this step can be skipped if the elastic stores are disabled).
相關(guān)PDF資料
PDF描述
DS21FT42N DATACOM, FRAMER, PBGA300
DS21FF42 DATACOM, FRAMER, PBGA300
DS21FF42N DATACOM, FRAMER, PBGA300
DS21FT44N DATACOM, FRAMER, PBGA300
DS21FT44 DATACOM, FRAMER, PBGA300
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
DS21FT42N 功能描述:網(wǎng)絡(luò)控制器與處理器 IC 4x4 16/4x3 12 Chnl T1/T1 Framer RoHS:否 制造商:Micrel 產(chǎn)品:Controller Area Network (CAN) 收發(fā)器數(shù)量: 數(shù)據(jù)速率: 電源電流(最大值):595 mA 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PBGA-400 封裝:Tray
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DS21FT44N 功能描述:網(wǎng)絡(luò)控制器與處理器 IC 4x4 16/4x3 12 Chnl E1/E1 Framer RoHS:否 制造商:Micrel 產(chǎn)品:Controller Area Network (CAN) 收發(fā)器數(shù)量: 數(shù)據(jù)速率: 電源電流(最大值):595 mA 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PBGA-400 封裝:Tray
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