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参数资料
| 型号： | DS21Q58LN |
| 英文描述： | E1 Quad Transceiver |
| 中文描述： | 素E1通道收发器 |
| 文件页数： | 27/74页 |
| 文件大小： | 647K |
| 代理商： | DS21Q58LN |
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DS21Q58 E1 Quad Transceiver
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9. STATUS AND INFORMATION REGISTERS
The DS21Q58 has a set of four registers that contain information about a framer’s real-time status. The registers
include status register 1 (SR1), status register 2 (SR2), receive information register (RIR), and synchronizer status
register (SSR).
When a particular event has occurred (or is occurring), the appropriate bit in one of these four registers is set to 1.
All the bits in the SR1, SR2, and RIR1 registers operate in a latched fashion. The SSR contents are not latched,
which means that if an event or an alarm occurs and a bit is set to 1 in any of the registers, the bit remains set until
the user reads that bit. The bit is cleared when it is read and is not set again until the event has occurred again (or,
in the case of the RUA1, RRA, RCL, and RLOS alarms, the bit remains set if the alarm is still present).
The user always precedes a read of the SR1, SR2, and RIR registers with a write. The byte written to the register
informs the framer which bits the user wishes to read and have cleared. The user writes a byte to one of these
registers with a 1 in the bit positions he or she wishes to read and a 0 in the bit positions he or she does not wish to
obtain the latest information on. When a 1 is written to a bit location, the read register updates with the latest
information. When a 0 is written to a bit position, the read register does not update and the previous value is held.
A write to the status and information registers is immediately followed by a read of the same register. The read
result should be logically ANDed with the mask byte that was just written, and this value should be written back into
the same register to ensure the bit clears. This second write step is necessary because the alarms and events in
the status registers occur asynchronously in respect to their access through the parallel port. This write-read-write
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 DS21Q58 with higher-order software languages.
The SSR register operates differently than the other three. It is a read-only register and reports the status of the
synchronizer in real time. This register is not latched and it is not necessary to precede a read of this register with a
write.
The SR1 and SR2 registers have the unique ability to initiate a hardware interrupt through the
INT
output pin. Each
of the alarms and events in SR1 and SR2 can be either masked or unmasked from the interrupt pin through
interrupt mask register 1 (IMR1) and interrupt mask register 2 (IMR2).
The interrupts caused by alarms in SR1 (RUA1, RRA, RCL, and RLOS) act differently than the interrupts caused
by events in SR1 and SR2 (RSA1, RDMA, RSA0, RSLIP, RMF, TMF, SEC, TAF, LOTC, and RCMF). The alarm-
caused interrupts force the
INT
pin low whenever the alarm changes state (i.e., the alarm goes active or inactive
according to the set/clear criteria in
Table 9-1
). The
INT
pin is allowed to return high (if no other interrupts are
present) when the user reads the alarm bit that caused the interrupt to occur, even if the alarm is still present.
The event-based interrupts force the
INT
pin low when the event occurs. The
INT
pin returns high () when the user
reads the event bit that caused the interrupt to occur. Furthermore, some event-based interrupts occur continuously
as long as the event is occurring (RSLIP, SEC, TMF, RMF, TAF, RAF, RCMF). Other event-based interrupts force
the
INT
pin low only once when the event is first detected (LOTC, PRSBD, RDMA, RSA1, RSA0), that is, the
PRBSD interrupt fires once when the receiver detects the PRBS pattern. If the receiver continues to receive the
PRBS pattern, no more interrupts are fired. If the receiver then detects that PRBS is no longer being sent, it resets
and, when it receives the PRBS pattern again, another interrupt is fired.
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相关代理商/技术参数 |
参数描述 |
|---|---|
| DS21Q58LN+ | 功能描述:网络控制器与处理器 IC Quad E1 Transceiver 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 |
| DS21Q59 | 制造商:MAXIM 制造商全称:Maxim Integrated Products 功能描述:RELIABILITY REPORT FOR DS21Q59, REV A2 |
| DS21Q59DK | 功能描述:网络开发工具 DS21Q59 Dev Kit RoHS:否 制造商:Rabbit Semiconductor 产品:Development Kits 类型:Ethernet to Wi-Fi Bridges 工具用于评估:RCM6600W 数据速率:20 Mbps, 40 Mbps 接口类型:802.11 b/g, Ethernet 工作电源电压:3.3 V |
| DS21Q59L | 功能描述:网络控制器与处理器 IC Quad E1 Transceiver 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 |
| DS21Q59L+ | 功能描述:网络控制器与处理器 IC Quad E1 Transceiver 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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