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参数资料
| 型号： | DS21FT42N |
| 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： | 80/115页 |
| 文件大小： | 534K |
| 代理商： | DS21FT42N |
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DS21FF42/DS21FT42
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Like the other status registers in the DS21Q42, the user will always proceed a read of any of the four
registers with a write. The byte written to the register will inform the DS21Q42 which of the latched bits
the user wishes to read and have cleared (the real time bits are not affected by writing to the status
register). The user will write a byte to one of these registers, with a one in the bit positions he or she
wishes to read and a zero in the bit positions he or she does not wish to obtain the latest information on.
When a one is written to a bit location, the read register will be updated with current value and it will be
cleared. When a zero is written to a bit position, the read register will not be updated and the previous
value will be held. A write to the status and information registers will be immediately followed by a read
of the same register. The read result should be logically AND’ed with the mask byte that was just written
and this value should be written back into the same register to insure that bit does indeed clear. This
second write step is necessary because the alarms and events in the status registers occur asynchronously
in respect to their access via the parallel port. This write–read–write (for polled driven access) or write–
read (for interrupt driven access) scheme allows an external microcontroller or microprocessor to
individually poll certain bits without disturbing the other bits in the register. This operation is key in
controlling the DS21Q42 with higher–order software languages.
Like the SR1 and SR2 status registers, the HSR register has the unique ability to initiate a hardware
interrupt via the INT* output pin. Each of the events in the HSR can be either masked or unmasked from
the interrupt pin via the HDLC Interrupt Mask Register (HIMR). Interrupts will force the INT* pin low
when the event occurs. The INT* pin will be allowed to return high (if no other interrupts are present)
when the user reads the event bit that caused the interrupt to occur.
BASIC OPERATION DETAILS
To allow the framer to properly source/receive data from/to the HDLC and BOC controller the legacy
FDL circuitry (which is described in Section 19.2) should be disabled and the following bits should be
programmed as shown:
TCR1.2 = 1 (source FDL data from the HDLC and BOC controller)
TBOC.6 = 1 (enable HDLC and BOC controller)
CCR2.5 = 0 (disable SLC–96 and D4 Fs–bit insertion)
CCR2.4 = 0 (disable legacy FDL zero stuffer)
CCR2.1 = 0 (disable SLC–96 reception)
CCR2.0 = 0 (disable legacy FDL zero stuffer)
IMR2.4 = 0 (disable legacy receive FDL buffer full interrupt)
IMR2.3 = 0 (disable legacy transmit FDL buffer empty interrupt)
IMR2.2 = 0 (disable legacy FDL match interrupt)
IMR2.1 = 0 (disable legacy FDL abort interrupt).
As a basic guideline for interpreting and sending both HDLC messages and BOC messages, the following
sequences can be applied:
相关PDF资料 |
PDF描述 |
|---|---|
| DS21FF42 | DATACOM, FRAMER, PBGA300 |
| DS21FF42N | DATACOM, FRAMER, PBGA300 |
| DS21FT44N | DATACOM, FRAMER, PBGA300 |
| DS21FT44 | DATACOM, FRAMER, PBGA300 |
| DS21Q352 | DATACOM, PCM TRANSCEIVER, PBGA256 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| 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 |
| DS21FT44+ | 功能描述:网络控制器与处理器 IC 4X3 E1 Framer E1 Framer E1 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 |
| DS21FT44N | 功能描述:网络控制器与处理器 IC 4x4 16/4x3 12 Chnl E1/E1 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 |
| DS21FT44N+ | 功能描述:网络控制器与处理器 IC 4x4 16/4x3 12 Chnl E1/E1 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 |
| DS21Q348 | 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 |
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