参数资料
型号: DS21FF44N
厂商: DALLAS SEMICONDUCTOR
元件分类: Digital Transmission Controller
英文描述: DATACOM, FRAMER, PBGA300
封装: 27 X 27 MM, BGA-300
文件页数: 37/110页
文件大小: 526K
代理商: DS21FF44N
DS21FT44/DS21FF44
32 of 110
9. PARALLEL PORT
The DS21Q44 is controlled via either a non–multiplexed (MUX = 0) or a multiplexed (MUX = 1) bus by
an external microcontroller or microprocessor. The DS21Q44 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 23 for more details.
10.
CONTROL, ID AND TEST REGISTERS
The operation of each framer within the DS21Q44 is configured via a set of ten control registers.
Typically, the control registers are only accessed when the system is first powered up. Once a channel in
the DS21Q44 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 six Common Control Registers (CCR1 to CCR6).
Each of the ten 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 one indicating that the DS21Q44 is present. The T1 pin–for–pin compatible version of the
DS21Q44 is the DS21Q42 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 4 bits of the IDR are used to display the die revision of the chip.
Power–Up Sequence
The DS21Q44 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 DS21Q44.
1. Clear framer’s register space by writing 00H to the addresses 00H through 0BFH.
2. Program required registers to achieve desired operating mode.
Note:
When emulating the DS21Q43 feature set (FMS = 1), the full address space (00H through 0BFH) must be
initialized. DS21Q43 emulation require address pin A7 to be used. FMS is tied to ground for the
DS21FF44/DS21FT44.
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).
相关PDF资料
PDF描述
DS21FT40N DATACOM, FRAMER, PBGA300
DS21FT40 DATACOM, FRAMER, PBGA300
DS21FT42 DATACOM, FRAMER, PBGA300
DS21FT42N DATACOM, FRAMER, PBGA300
DS21FF42 DATACOM, FRAMER, PBGA300
相关代理商/技术参数
参数描述
DS21FT40 制造商:DALLAS 制造商全称:Dallas Semiconductor 功能描述:Four x Three 12 Channel E1 Framer
DS21FT40N 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述:
DS21FT42 功能描述:网络控制器与处理器 IC 4x4 16/4x3 12 Chnl T1/T1 Framer RoHS:否 制造商:Micrel 产品:Controller Area Network (CAN) 收发器数量: 数据速率: 电源电流(最大值):595 mA 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:PBGA-400 封装:Tray
DS21FT42N 功能描述:网络控制器与处理器 IC 4x4 16/4x3 12 Chnl T1/T1 Framer RoHS:否 制造商:Micrel 产品:Controller Area Network (CAN) 收发器数量: 数据速率: 电源电流(最大值):595 mA 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:PBGA-400 封装:Tray
DS21FT44 功能描述:网络控制器与处理器 IC RoHS:否 制造商:Micrel 产品:Controller Area Network (CAN) 收发器数量: 数据速率: 电源电流(最大值):595 mA 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:PBGA-400 封装:Tray