DS21552L+ Maxim Integrated Products, DS21552L+ Datasheet - Page 68

• Manufacturer Part Number: DS21552L+
• Description: IC TXRX T1 1-CHIP 5V 100-LQFP
• Manufacturer: Maxim Integrated Products

Specifications of DS21552L+

• Function: Single-Chip Transceiver
• Interface: E1, HDLC, J1, T1
• Number Of Circuits: 1
• Voltage - Supply: 4.75 V ~ 5.25 V
• Current - Supply: 75mA
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 100-LQFP
• Includes: DSX-1 and CSU Line Build-Out Generator, HDLC Controller, In-Band Loop Code Generator and Detector
• Product: Framer
• Number Of Transceivers: 1
• Data Rate: 64 Kbps
• Supply Voltage (max): 3.465 V
• Supply Voltage (min): 3.135 V
• Supply Current (max): 75 mA (Typ)
• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: 0 C
• Mounting Style: SMD/SMT
• Ic Interface Type: Parallel, Serial
• Supply Voltage Range: 4.75V To 5.25V
• Operating Temperature Range: 0°C To +70°C
• Digital Ic Case Style: LQFP
• No. Of Pins: 100
• Filter Terminals: SMD
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power (watts): -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Table 15-2 HDLC/BOC CONTROLLER REGISTERS
HDLC Control Register (HCR)
HDLC Status Register (HSR)
HDLC Interrupt Mask Register (HIMR)
Receive HDLC Register (RHIR)
Receive BOC Register (RBOC)
Receive HDLC FIFO Register (RHFR)
Receive HDLC DS0 Control Register 1 (RDC1)
Receive HDLC DS0 Control Register 2 (RDC2)
Transmit HDLC Register (THIR)
Transmit BOC Register (TBOC)
Transmit HDLC FIFO Register (THFR)
Transmit HDLC DS0 Control Register 1 (TDC1)
Transmit HDLC DS0 Control Register 2 (TDC2)
15.3.2 STATUS REGISTER FOR THE HDLC
Four of the HDLC/BOC controller registers (HSR, RHIR, RBOC, and THIR) provide status information.
When a particular event has occurred (or is occurring), the appropriate bit in one of these four registers
will be set to a one. Some of the bits in these four HDLC status registers are latched and some are real
time bits that are not latched. Section 15.3.2 contains register descriptions that list which bits are latched
and which are not. With the latched bits, when an event occurs and a bit is set to a one, it 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. The real time bits report the current instantaneous conditions that are occurring
and the history of these bits is not latched.
Like the other status registers, 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 device 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 device with
higher–order software languages.
NAME
68 of 137
general control over the HDLC and BOC controllers
key status information for both transmit and receive directions
allows/stops status bits to/from causing an interrupt
status information on receive HDLC controller
status information on receive BOC controller
access to 64–byte HDLC FIFO in receive direction
controls the HDLC function when used on DS0 channels
controls the HDLC function when used on DS0 channels
status information on transmit HDLC controller
enables/disables transmission of BOC codes
access to 64–byte HDLC FIFO in transmit direction
controls the HDLC function when used on DS0 channels
controls the HDLC function when used on DS0 channels
FUNCTION
DS21352/DS21552