Bt8370/8375/8376
3.13 Transmit Sa-Byte Buffers
Fully Integrated T1/E1 Framer and Line Interface
3.13 Transmit Sa-Byte Buffers
Unused bits indicated by a dash (—) are reserved and should be written to 0. Writing to reserved bits has no
effect.
Five transmit Sa-Byte buffers (TSA4–TSA8) are used to insert Sa-bits in TS0. The entire group of 40 bits is
sampled every 16 frames, coincident with the TMF interrupt boundary [addr 008]. Bit 0 from each TSA register
is then inserted during frame 1: bit 1 is inserted during frame 3; bit 2 is inserted during frame 5; and so on. This
gives the processor a maximum of 2 ms after the TMF interrupt to write new Sa-Byte buffer values. Transmit
Sa-bits maintain a fixed relationship to the transmit CRC multiframe.
07B—Transmit Sa4 Byte Buffer (TSA4)
7
6
5
4
3
2
1
0
TSA4[7]
TSA4[6]
TSA4[5]
TSA4[4]
TSA4[3]
TSA4[2]
TSA4[1]
TSA4[0]
TSA4[7]
Sa4 bit transmitted in frame 15
Sa4 bit transmitted in frame 13
Sa4 bit transmitted in frame 11
Sa4 bit transmitted in frame 9
Sa4 bit transmitted in frame 7
Sa4 bit transmitted in frame 5
Sa4 bit transmitted in frame 3
Sa4 bit transmitted in frame 1
TSA4[6]
TSA4[5]
TSA4[4]
TSA4[3]
TSA4[2]
TSA4[1]
TSA4[0]
07C—Transmit Sa5 Byte Buffer (TSA5)
7
6
5
4
3
2
1
0
TSA5[7]
TSA5[6]
TSA5[5]
TSA5[4]
TSA5[3]
TSA5[2]
TSA5[1]
TSA5[0]
TSA5[7]
Sa5 bit transmitted in frame 15
Sa5 bit transmitted in frame 13
Sa5 bit transmitted in frame 11
Sa5 bit transmitted in frame 9
Sa5 bit transmitted in frame 7
Sa5 bit transmitted in frame 5
Sa5 bit transmitted in frame 3
Sa5 bit transmitted in frame 1
TSA5[6]
TSA5[5]
TSA5[4]
TSA5[3]
TSA5[2]
TSA5[1]
TSA5[0]
3-80
Conexant
N8370DSE