SAF82525 Infineon Technologies AG, SAF82525 Datasheet - Page 49

• Manufacturer Part Number: SAF82525
• Description: Data Communications ICs
• Manufacturer: Infineon Technologies AG

5
The two serial interfaces of the HSCX provide two fully independent communications
channels, supporting layer-1 functions to a high degree by various means of clock generation
and clock recovery.
5.1 Clock Modes
The HSCX includes an internal Oscillator (OSC) as well as independent Baudrate Generator
(BRG) and Digital Phase Locked Loop (DPLL) circuitry for each serial channel.
The transmit and receive clock can be either generated
Totally, there are 8 different clocking modes programmable via the CCR1 register, providing a
wide variety of clock generation and clock pin functions, as shown in table 5.
Table 5
Overview of Clock Modes
Type
Receive
Clock
Transmit
Clock
The transmit clock pins (T CLK) may also output clock or control signal in certain clock modes
if programmed as outputs via the CCR2 register (TIO bit set).
The clocking source for the DPLL’s is always the internal BRG; the scaling factor (divider) of
the BRG can be programmed through CCR2 and BGR registers between 1,2,4,6. . .2048.
The HSCX system clock is always derived from the transmit clock thus eliminating the need
for additional clock sources.
Clock Mode 0 (External Clocks)
Separate, externally generated receive and transmit clocks are forwarded to the HSCX via
their respective pins.
Semiconductor Group
– externally, and supplied via the R CLK and/or T CLK pins, or
– internally, by means of the
* OSC and/or BRG, and
* DPLL, recovering the receive (and optionally transmit) clock from the received data
stream if an external crystal is connected to the R CLKA-A CLKA pins.
Serial Interface (Layer-1 Functions)
Source
R CLK Pins
DPLL
OSC
T CLK Pins
R CLK Pins
DPLL
BRG/16
OSC
Clock
Generation
Externally
Internally
Externally
Internally
49
Mode
0, 1, 5
2, 3, 6, 7
4
0, 2, 6
1, 5
3, 7
2, 6
4
SAB 82525
SAB 82526
SAF 82525
SAF 82526