參數(shù)資料
型號: DS21348T
廠商: DALLAS SEMICONDUCTOR
元件分類: Digital Transmission Interface
英文描述: DATACOM, PCM TRANSCEIVER, PQFP44
封裝: TQFP-44
文件頁數(shù): 22/67頁
文件大?。?/td> 339K
代理商: DS21348T
DS21348/Q348
29 of 67
SYMBOL
POSITION
NAME AND DESCRIPTION
RJAB
CCR6.3
RCLK Jitter Attenuator Bypass. This control bit allows the
receive recovered clock and data to bypass the jitter attenuation
while still allowing the BPCLK output to use the jitter
attenuator. See Figure 3-1 for details.
0 = disabled
1 = enabled
ECRS2
CCR6.2
Error Count Register Select 2. See Section 8.4 for details.
ECRS1
CCR6.1
Error Count Register Select 1. See Section 8.4 for details.
ECRS0
CCR6.0
Error Count Register Select 0. See Section 8.4 for details.
7. STATUS REGISTERS
There are three registers that contain information on the current real time status of the device, Status
Register (SR) and Receive Information Registers 1 & 2 (RIR1/RIR2). When a particular event has
occurred (or is occurring), the appropriate bit in one of these three registers will be set to a one. Some of
the bits in SR, RIR1, and RIR2 are latched bits and some are real time bits. The register descriptions
below list which status bits are latched and which are real time bits. For latched status bits, when an
event or an alarm occurs the bit is set to a one and will remain set until the user reads that bit. The bit will
be cleared when it is read and it will not be set again until the event has occurred again. Two of the
latched status bits (RUA1 & RCL) will remain set after reading if the alarm is still present.
The user will always precede a read of any of the three status registers with a write. The byte written to
the register will inform the DS21348 which bits the user wishes to read and have cleared. The user will
write a byte to one of these registers with a one in the bit positions to be read and a zero in the other bit
positions. When a one is written to a bit location, that location will be updated with the latest information.
When a zero is written to a bit position, that bit position 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 with
respect to their access via 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 DS21348 with higher–order software languages.
The bits in the SR register have the unique ability to initiate a hardware interrupt via the INT* output pin.
Each of the alarms and events in the SR can be either masked or unmasked from the interrupt pin via the
Interrupt Mask Register (IMR). The interrupts caused by the RCL, RUA1 and LOTC bits in SR act
differently than the interrupts caused by the other status bits in SR. The RCL, RUA1 and LOTC bits will
force the INT* pin low whenever they change state (i.e. go active or inactive). The INT* pin will be
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 other status bits in SR can force the INT* pin low
when they are set. 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.
相關(guān)PDF資料
PDF描述
DS21348TN DATACOM, PCM TRANSCEIVER, PQFP44
DS21348G DATACOM, PCM TRANSCEIVER, BGA49
DS21Q348N DATACOM, PCM TRANSCEIVER, PBGA144
DS21Q348 DATACOM, PCM TRANSCEIVER, PBGA144
DS21352L DATACOM, PCM TRANSCEIVER, PQFP100
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
DS21348T+ 功能描述:網(wǎng)絡(luò)控制器與處理器 IC 3.3V E1/T1/J1 Line Interface 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
DS21348TB 功能描述:網(wǎng)絡(luò)控制器與處理器 IC 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
DS21348TN 功能描述:網(wǎng)絡(luò)控制器與處理器 IC 3.3V E1/T1/J1 Line Interface 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
DS21348TN+ 功能描述:網(wǎng)絡(luò)控制器與處理器 IC 3.3V E1/T1/J1 Line Interface 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
DS21348TNB 功能描述:網(wǎng)絡(luò)控制器與處理器 IC 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