TDA5240 Datasheet, PDF (68/284 Pages) Infineon Technologies AG – Enhanced Sensitivity Multi-Channel Quad-Configuration Receiver

TDA5240
Functional Description
The synchronization search time T₃ is the time the receiver requires to search for a
pattern in an incoming data stream and needs to be considered in the receivers start-up
phase. The minimum value of the search time out length is the consequence of the
system latency time T₁, the RUNIN length and the time of asynchronism between
transmitter and receiver.
This means, that for the minimum length of register value for SYSRCTO, the value 2 bits
plus 12.5 µs plus the RUNIN length, which is set in the x_CDRRI register, plus 2 bits (to
consider worst case RUNIN patterns and TX-RX asynchronism) have to be used. To
reach data rate and duty cycle errors, 10% of the overall sum must be added.
SYSRCT0
=
ro
u
n
d
u
p_⎝⎛
⎛
⎝
⎛
⎝
1----2---.-5---μ_----s-
T_bit
+
2
+
R
U
N
L
E
N
+
2_⎠⎞
⋅ 16_⎠⎞
⋅ 1.1_⎠⎞
A second important system parameter that must be considered, is the minimal Inter-
Frame Time (time between two data frames). This time is equal to the time T₂ and has a
length of 1.5 or 2 bits¹⁾. The EOM to PLL resynchronization time is negligible in case
INITDRXES is disabled. Otherwise T₁ has to be added.²⁾
Note that the described Inter-Frame Time is based on the input pattern with equal signal
power in the following data frame; in other cases, the Inter-Frame Time can vary from
the calculated value.
T_{Inter – Frame}
=
1.5 T _{b i t}
+
⎛
⎜
0.5
T_b1i⁾_{t⎟⎞}
⎝ ₀⎠
+
⎛
⎜
T₁₂
)_⎞
⎟
⎝ ₀⎠
1) see previous footnote
2) in case INITDRXES is enabled
Data Sheet
68
V4.0, 2010-02-19