MAX9260 Maxim, MAX9260 Datasheet - Page 29

• Manufacturer Part Number: MAX9260
• Description: The MAX9259/MAX9260 chipset presents Maxim's gigabit multimedia serial link (GMSL) technology
• Manufacturer: Maxim

Table 5. MAX9260 f
Choose MCLKDIV values so that f
than 60MHz. MCLK frequencies derived from PCLK_
(MCLKSRC = 0) are not affected by spread-spectrum
settings in the deserializer (MAX9260). Enabling spread
spectrum in the serializer (MAX9259), however, intro-
duces spread spectrum into MCLK. Spread-spectrum
settings of either device do not affect MCLK frequencies
derived from the internal oscillator. The internal oscilla-
tor frequency ranges from 100MHz to 150MHz over all
process corners and operating conditions.
The FC uses the control link to send and receive control
data over the STP link simultaneously with the high-speed
data. Configuring the CDS pin allows the FC to control the
link from either the MAX9259 or the MAX9260 side to sup-
port video-display or image-sensing applications.
The control link between the FC and the MAX9259 or
MAX9260 runs in base mode or bypass mode accord-
ing to the mode selection (MS) input of the device con-
nected to the FC. Base mode is a half-duplex control link
and the bypass mode is a full-duplex control link. In base
mode, the FC is the host and accesses the registers of
both the MAX9259 and MAX9260 from either side of the
link by using the GMSL UART protocol. The FC can also
program the peripherals on the remote side by sending
the UART packets to the MAX9259 or MAX9260, with
UART packets converted to I
remote side of the link (MAX9260 for LCD or MAX9259
for image-sensing applications). The FC communicates
with a UART peripheral in base mode (through INTTYPE
register settings) using the half-duplex default GMSL
UART protocol of the MAX9259 and MAX9260. The
device addresses of the MAX9259 and MAX9260 in the
base mode are programmable. The default values are
0x80 and 0x90, respectively.
In base mode, when the peripheral interface uses I
(default), the MAX9259/MAX9260 only convert packets
that have device addresses different from those of the
Control-Channel and Register Programming
(REGISTER 0x12, D7)
MCLKSRC SETTING
Gigabit Multimedia Serial Link with Spread
Spectrum and Full-Duplex Control Channel
0
1
______________________________________________________________________________________
SRC
2
C by the device on the
Settings
DATA-RATE SETTING
MCLK
High speed
Low speed
is not greater
—
2
C
MAX9259 or MAX9260 to I
is the same as the original UART bit rate.
In bypass mode, the FC bypasses the MAX9259/
MAX9260 and communicates with the peripherals direct-
ly using its own defined UART protocol. The FC cannot
access the MAX9259/MAX9260’s registers in this mode.
Peripherals accessed through the forward control chan-
nel using the UART interface need to handle at least one
PCLK_ period of jitter due to the asynchronous sampling
of the UART signal by PCLK_.
The MAX9259 embeds control signals going to the
MAX9260 in the high-speed forward link. Do not send
a low value longer than 100Fs in either base or bypass
mode. The MAX9260 uses a proprietary differential line
coding to send signals back towards the MAX9259. The
speed of the control link ranges from 100kbps to 1Mbps
in both directions. The MAX9259/MAX9260 automatically
detect the control-channel bit rate in base mode. Packet
bit rates can vary up to 3.5x from the previous bit rate
(see the Changing the Data Frequency section). Figure
24 shows the UART protocol for writing and reading in
base mode between the FC and the MAX9259/MAX9260.
Figure 25 shows the UART data format. Even parity is
used. Figures 26 and 27 detail the formats of the SYNC
byte (0x79) and ACK byte (0xC3). The FC and the con-
nected slave chip generate the SYNC byte and ACK
byte, respectively. Certain events such as device wake-
up and interrupt generate signals on the control path and
should be ignored by the FC. All data written to the inter-
nal registers do not take affect until after the acknowl-
edge byte is sent. This allows the FC to verify that write
commands are processed without error, even if the result
of the write command directly affects the serial link. The
slave uses the SYNC byte to synchronize with the host
UART data rate automatically. If the INT or MS inputs of
the MAX9260 toggles while there is control-channel com-
munication, the control-channel communication can be
corrupted. In the event of a missed acknowledge, the FC
BIT-WIDTH SETTING
24-bit mode
32-bit mode
24-bit mode
32-bit mode
—
2
C. The converted I
FREQUENCY (f
Internal oscillator
MCLK SOURCE
3 x f
4 x f
6 x f
8 x f
(120MHz typ)
PCLKOUT
PCLKOUT
PCLKOUT
PCLKOUT
2
SRC
C bit rate
)
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