MAX-M10S-Integration manual
The TIMEPULSE pin is shared with SAFEBOOT_N pin. If this pin is low at receiver startup,
the receiver enters safeboot mode. In normal operation, this pin is used for time pulse. Make
sure there is no load at this pin, which could cause the pin being low at startup.
2.3.3.4 LNA_EN
The  system  can  turn  an  optional  external  LNA  on  and  off  using  the  LNA_EN  signal  to  optimize
the power consumption.  The  LNA_EN  signal  is  also  used  internally in MAX-M10S  to  control the
integrated LNA. The LNA is turned on when LNA_EN is "high". The polarity cannot be changed.
The LNA_EN signal can also be used as a part of antenna supervisor circuit to control an external
LNA or antenna power supply.
2.3.3.5 EXTINT
MAX-M10S supports external interrupts at the EXTINT pin. The EXTINT pin has a fixed input voltage
threshold with respect to V_IO. It can be used for functions such as accurate external Frequency
assistance, Time assistance and Time mark reporting.
The EXTINT pin enables External control for host-controlled on/off operation of the receiver, and as
a wake-up source for power save mode on/off operation (PSMOO). If configured for host-controlled
on/off operation, the internal pull-up is disabled. Make sure the EXTINT input is always driven within
the defined voltage level by the host.
The EXTINT pin can also be configured for another functionality.
EXTINT functionality is only available at the EXTINT pin.
2.3.3.6 TX_READY
The MAX-M10S has an internal message buffer for storing bytes to be sent to the host application.
TX-ready feature in TX_READY pin enables I2C to have associated signals to indicate that the buffer
has  bytes  to  be  transmitted.  The  host  application  can  wait  on  the  signal  instead  of  polling  the
interface. Each interface has its own indicator signal that can be assigned to any PIO/pin. Each signal
is associated to one interface and cannot be shared.
The polarity of the signal (active-low or active-high) and the threshold for amount of bytes in the
buffer can be configured with UBX-CFG-TXREADY configuration items. When the number of bytes in
the buffer reaches the threshold, the corresponding signal becomes active. The signal stays active
until all of the bytes in the buffer have been transferred. The receiver has additional small transmit
buffer for each interface. Up to 16 bytes may still need to be transferred to the host after the TX-
ready signal has become inactive.
If  a  PIO  to  be  configured  is  invalid  or  already  in  use,  the  configuration  for  the  TX_READY  pin  is
ignored. The rest of the interface configuration is still applied if valid. The acknowledge message
does  not  indicate  if  the  TX_READY  pin  configuration  was  successfully  set,  it  only  indicates  the
successful  configuration  of  the  interface.  To  verify  the  configuration  of  the  TX_READY  pin,  the
interface configuration should be read back to check the setting of the TX_READY pin. The setting
is set to disabled/all zero if the configuration failed.
The  threshold  when  TX-ready  signal  is  activated  should  not  be  set  above  2  kB.  Otherwise,  it  is
possible that the internal message buffer gets full and some messages are discarded.
2.3.3.6.1 Extended TX timeout
If  the  host  does  not  communicate  over  I2C  for  more  than  approximately  2  seconds,  the  device
assumes  that  the  host  is  no  longer  using  this  interface and  no  more  packets are scheduled  for
this interface. This mechanism can be changed by enabling "extended TX timeouts", in which case
the receiver delays idling the interface until the allocated and undelivered bytes for this interface
UBX-20053088 - R03
2 Receiver functionality Page 25 of 89
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