DS21Q55N Maxim Integrated Products, DS21Q55N Datasheet - Page 139

• Manufacturer Part Number: DS21Q55N
• Description: Framer E1/J1/T1 3.3V 256-Pin BGA
• Manufacturer: Maxim Integrated Products

Specifications of DS21Q55N

• Package: 256BGA
• Number Of Transceivers: 4
• Standard Framing Format: E1|J1|T1
• Maximum Supply Current: 75(Typ) mA
• Minimum Single Supply Voltage: 3.135 V
• Maximum Single Supply Voltage: 3.465 V

Register Name:
Register Description:
Register Address:
Bit #
Name
Default
Bit 0/Transmit FIFO Not Full Condition (TNF). Set when the transmit 128-byte FIFO has at least 1 byte
available.
Bit 1/Transmit FIFO Below Low-Watermark Condition (TLWM). Set when the transmit 128-byte FIFO
empties beyond the low watermark as defined by the transmit low-watermark register (TLWMR).
Bit 2/Receive FIFO Not Empty Condition (RNE). Set when the receive 128-byte FIFO has at least 1 byte
available for a read.
Bit 3/Receive FIFO Above High-Watermark Condition (RHWM). Set when the receive 128-byte FIFO fills
beyond the high watermark as defined by the receive high-watermark register (RHWMR).
Bit 4/Receive Packet-Start Event (RPS). Set when the HDLC controller detects an opening byte. This is a latched
bit and is cleared when read.
Bit 5/Receive Packet-End Event (RPE). Set when the HDLC controller detects either the finish of a valid
message (i.e., CRC check complete) or when the controller has experienced a message fault such as a CRC
checking error, or an overrun condition, or an abort has been seen. This is a latched bit and is cleared when read.
Bit 6/Transmit Message-End Event (TMEND). Set when the transmit HDLC controller has finished sending a
message. This is a latched bit and is cleared when read.
—
7
0
TMEND
SR6, SR7
HDLC #1 Status Register 6
HDLC #2 Status Register 7
20h, 22h
6
0
RPE
5
0
RPS
4
0
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RHWM
0
3
RNE
2
0
TLWM
1
0
TNF
0
0