Uart Control Channel; Overview; Base Mode; Bypass Mode - Analog Devices MAX96752 User Manual

UART Control Channel

Overview

The primary UART control channel is used to provide access to both serializer and deserializer registers across the
GMSL link. This provides flexibility where the registers for both serializer and deserializer are accessible from
whichever side the main microcontroller resides (for camera applications, the main microcontroller typically
resides on the deserializer side).
The pass-through UART channels are used to send UART data across the GMSL Link. The pass-through channels can
access the remote-side devices connected through the corresponding pass-through ports but cannot access the
serializer or deserializer registers.
Note: When making changes to any of the serializer or deserializer UART configuration, such as enabling or
disabling an UART channels, a 10µs delay from the write acknowledgement (ACK) to the next transaction is
required.

Base Mode

Base mode allows the device registers of both the serializer and deserializer to be accessed by the host
microcontroller. It is the default mode for the primary UART control channel on power-up.

Bypass Mode

In Bypass mode, both the serializer and deserializer ignore all UART commands from the microcontroller. The
serializer/deserializer registers are not accessible, and the microcontroller can freely communicate with any
peripherals using its defined UART protocol. In this mode, the UART commands are still sent over the GMSL link.
This mode prevents inadvertent programming of the serializer/deserializer registers and can be switched in and
out of during normal operation.

Port Access and Routing

The MFPs shown in the table below are used for the UART primary and pass-through channels.
Table 12.
MAX96752 MFP pins for UART
Pin Default Function
40 GPIO03
42 GPIO05
27 GPIO06
29 GPIO08
8 SDA _RX
9 SCL_TX
1 I2CSEL
On power-up the device should be set to UART mode via the I2CSEL pin state. The function names in the above MFP
table and ensuing UART sections assume the device has been configured for UART mode.
By default, the primary UART control channel lines are brought out on MFP8 and MFP9 for RX and TX, respectively.
The user can disable the primary control channel's line access by setting field DIS_LOCAL_CC in register 0x01. One
can also disable access to remote device control by setting field DIS_REM_CC in register 0x01.
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UART Function #1
RX1
TX1
RX2
TX2
RX
TX
I2CSEL
Enable UART pass-through via register
Enable UART pass-through via register
Enable UART pass-through via register
Enable UART pass-through via register
I2C or UART function selected via I2CSEL pin
I2C or UART function selected via I2CSEL pin
Selects I C or UART on power-up. Latch low to select
2
UART.
Notes
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