tza3017hw NXP Semiconductors, tza3017hw Datasheet - Page 11

• Manufacturer Part Number: tza3017hw
• Description: 30 Mbits/s Up To 3.2 Gbits/s A-rate Fibre Optic Transmitter
• Manufacturer: NXP Semiconductors

Philips Semiconductors
The following examples refer to the flowchart in Fig.5.
Example 1: An SDH or SONET link has a bit rate of 2488.32 Mbits/s (STM16/OC48) that corresponds to octave 0 and
an M division factor of 1. If the reference frequency f
required to be 4. The initial values for integer n and fractional part k are calculated using the equation:
In this example, n = 128 and k = 0. Since k is 0, fractional functionality is not required, so bit NILFRAC in I
register FRACN2 should be set to logic 1; see Table 19. N = n
values of R = 4, M = 1 and N = 256 are set by I
(Table 17) and MAINDIV0 (Table 18).
Example 2: An SDH or SONET link has a bit rate of 2666.057143 Mbits/s (15/14
with FEC) that corresponds to octave 0 and an M division factor of 1. If f
the division factor R is required to be 2. The values for n and k are calculated as follows:
In this example, n = 137 and k = 0.1428571. Fractional functionality is required, so bit NILFRAC in I
register FRACN2 should be set to logic 0. Since k is less than 0.25, k is corrected to k = k
corrected to N = n
are set by I
FRACN2 (Table 19), FRACN1 (Table 20) and FRACN0 (Table 21). The FEC bit rate is usually rounded up to
2666.06 Mbits/s, which actually gives a different value for k than in this example.
Example 3: A Fibre Channel link has a bit rate of 1062.50 Mbits/s that corresponds to octave 1 and an M division factor
of 2. If f
calculated as follows:
In this example, n = 109 and k = 0.3107. Fractional functionality is required, so bit NILFRAC in I
should be set to logic 0. Since k is greater than 0.25 and less than 0.75, k does not need to be corrected. N is corrected
to N = n
I
(Table 19), FRACN1 (Table 20) and FRACN0 (Table 21).
Example 4: A non standard transmission link has a bit rate of 3012 Mbits/s that corresponds to octave 0 and an
M division factor of 1. If f
for n and k are calculated as follows:
In this example, n = 146 and k = 0.9268293. Fractional functionality is required, so bit NILFRAC in I
register FRACN2 should be set to logic 0. Since k is greater than 0.75, k is corrected to k = k
is corrected to N = n
are set by I
FRACN2 (Table 19), FRACN1 (Table 20) and FRACN0 (Table 21).
If the I
by pins DR0, DR1 and DR2 using an external reference clock frequency of 19.44 MHz.
2003 May 14
n.k
n.k
2
C-bus registers SYNTHCNF (Table 22), DIVCNF (Table 16), MAINDIV1 (Table 17), MAINDIV0 (Table 18), FRACN2
30 Mbits/s up to 3.2 Gbits/s
A-rate fibre optic transmitter
=
=
2
bit rate M R
--------------------------------------- -
bit rate M R
--------------------------------------- -
C-bus is not used, the clock synthesizer can be set up for the eight pre-programmed bit rates shown in Table 3,
ref
at pins CREF and CREFQ is 19.44 MHz, the division factor R is required to be 1. The values for n and k are
2 = 218. The resulting values of R = 1, M = 2, N = 218 and K = 01 0011 1110 0010 1000 0001 are set by
2
2
C-bus registers SYNTHCNF (Table 22), DIVCNF (Table 16), MAINDIV1 (Table 17), MAINDIV0 (Table 18),
C-bus registers SYNTHCNF (Table 22), DIVCNF (Table 16), MAINDIV1 (Table 17), MAINDIV0 (Table 18),
f
f
ref
ref
2
n.k
2
=
=
ref
1 = 273. The resulting values of R = 2, M = 1, N = 273 and K = 10 1001 0010 0100 1001 0011
2488.32 Mbits 1 4
-------------------------------------------------------- -
2666.05714283 Mbits 1 2
---------------------------------------------------------------------------- -
1 = 293. The resulting values of R = 1, M = 1, N = 293 and K = 01 1011 0101 0001 0010 1011
=
at pins CREF and CREFQ is 20.50 MHz, the division factor R is required to be 1. The values
bit rate M R
--------------------------------------- -
77.76 MHz
38.88 MHz
f
ref
n.k
=
bit rate M R
--------------------------------------- -
=
2
C-bus registers SYNTHCNF (Table 22), DIVCNF (Table 16), MAINDIV1
1062.50 Mbits
-------------------------------------------------------- -
=
f
128
ref
ref
19.44 MHz
at pins CREF and CREFQ is 77.76 MHz, the division factor R is
=
11
137.1428571
=
2 = 256 with no further correction required. The resulting
3012 Mbits 1 1
----------------------------------------------- -
2 1
20.50 MHz
=
ref
109.3106996
at pins CREF and CREFQ is 38.88 MHz,
2488.32 Mbits/s) (STM16/OC48 link
=
146.9268293
0.5 = 0.6428571, and N is
2
0.5 = 0.4268293, and N
C-bus register FRACN2
TZA3017HW
Product specification
2
2
C-bus
C-bus
2
C-bus