DS21FF44 Maxim Integrated Products, DS21FF44 Datasheet - Page 66

• Manufacturer Part Number: DS21FF44
• Description: IC FRAMER E1 4X4 16CH 300-BGA
• Manufacturer: Maxim Integrated Products

Specifications of DS21FF44

• Controller Type: E1 Framer
• Interface: Parallel/Serial
• Voltage - Supply: 2.97 V ~ 3.63 V
• Current - Supply: 300mA
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 300-BGA
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

18.2. Internal Register Scheme Based On Double-Frame
On the receive side, the RAF and RNAF registers will always report the data as it received in the
Additional and International bit locations. The RAF and RNAF registers are updated with the setting of
the Receive Align Frame bit in Status Register 2 (SR2.6). The host can use the SR2.6 bit to know when
to read the RAF and RNAF registers. It has 250µs to retrieve the data before it is lost.
On the transmit side, data is sampled from the TAF and TNAF registers with the setting of the Transmit
Align Frame bit in Status Register 2 (SR2.3). The host can use the SR2.3 bit to know when to update the
TAF and TNAF registers. It has 250µs to update the data or else the old data will be retransmitted. Data
in the Si bit position will be overwritten if the framer is programmed: (1) to source the Si bits from the
TSER pin, (2) in the CRC4 mode, or (3) have automatic E-bit insertion enabled. Data in the Sa bit
position will be overwritten if any of the TCR2.3 to TCR2.7 bits are set to one (please see Section 18.1
for details). For more details, see the register descriptions for TCR1 and TCR2 and the transmit data flow
diagram in Section 18.
RAF: RECEIVE ALIGN FRAME REGISTER (Address = 2F Hex)
RNAF: RECEIVE NON-ALIGN FRAME REGISTER (Address = 1F Hex)
(MSB)
(MSB)
SYMBOL
SYMBOL
Si
Si
Sa4
Sa5
Sa6
Sa7
Sa8
Si
Si
A
0
0
1
1
0
1
1
1
1
0
POSITION
POSITION
RNAF.7
RNAF.6
RNAF.5
RNAF.4
RNAF.3
RNAF.2
RNAF.1
RNAF.0
RAF.7
RAF.6
RAF.5
RAF.4
RAF.3
RAF.2
RAF.1
RAF.0
A
0
International Bit
Frame Alignment Signal Bit
Frame Alignment Signal Bit
Frame Alignment Signal Bit
Frame Alignment Signal Bit
Frame Alignment Signal Bit
Frame Alignment Signal Bit
Frame Alignment Signal Bit
International Bit
Frame Non-Alignment Signal Bit
Remote Alarm
Additional Bit 4
Additional Bit 5
Additional Bit 6
Additional Bit 7
Additional Bit 8
Sa4
1
66 of 117
Sa5
NAME AND DESCRIPTION
NAME AND DESCRIPTION
1
Sa6
0
Sa7
1
(LSB)
(LSB)
Sa8
1