English
Language : 

XR21B1424_17 Datasheet, PDF (60/64 Pages) Exar Corporation – Enhanced 4-Ch Full-Speed USB UART
◁
SUSPEND_STATE_LSB (0x030) - Read/Write OTP
This register configures the state of the GPIO pins during suspend state.
Bit
7:6
5
4
3
2
1:0
Default
Description
0
Not used
0
GPIO2/DSR#
0: Corresponding bit set to logic ’0’ during suspend if USE_SUSPEND = ’1’
1: Corresponding bit set to logic ’1’ during suspend if USE_SUSPEND = ’1’
0
GPIO3/DTR#
0: Corresponding bit set to logic ’0’ during suspend if USE_SUSPEND = ’1’
1: Corresponding bit set to logic ’1’ during suspend if USE_SUSPEND = ’1’
0
GPIO0/RI#
0: Corresponding bit set to logic ’0’ during suspend if USE_SUSPEND = ’1’
1: Corresponding bit set to logic ’1’ during suspend if USE_SUSPEND = ’1’
0
GPIO1/CD#
0: Corresponding bit set to logic ’0’ during suspend if USE_SUSPEND = ’1’
1: Corresponding bit set to logic ’1’ during suspend if USE_SUSPEND = ’1’
0
Not used
XR21B1424
SUSPEND_MODE_MSB (0x031) - Read/Write OTP
This register configures the mode of the GPIO pins during suspend state. Note that RX and TX data pins are not controlled
by SUSPEND_STATE. USE_SUSPEND is not a physical pin, but instead acts as the control for pins in the suspended state
and is in the most significant bit position of SUSPEND_MODE_MSB.
Bit
7
6
5:4
3
2
1
0
Default
Description
0
GPIO9/RXT
0: Corresponding GPIO is push-pull output during suspend if USE_SUSPEND = ’1’
1: Corresponding GPIO is open-drain output during suspend if USE_SUSPEND = ’1’
0
GPIO8/TXT
0: Corresponding GPIO is push-pull output during suspend if USE_SUSPEND = ’1’
1: Corresponding GPIO is open-drain output during suspend if USE_SUSPEND = ’1’
0
Not used
0
GPIO7/RS485
0: Corresponding GPIO is push-pull output during suspend if USE_SUSPEND = ’1’
1: Corresponding GPIO is open-drain output during suspend if USE_SUSPEND = ’1’
0
GPIO4/CTS#
0: Corresponding GPIO is push-pull output during suspend if USE_SUSPEND = ’1’
1: Corresponding GPIO is open-drain output during suspend if USE_SUSPEND = ’1’
0
GPIO5/RTS#/RS485
0: Corresponding GPIO is push-pull output during suspend if USE_SUSPEND = ’1’
1: Corresponding GPIO is open-drain output during suspend if USE_SUSPEND = ’1’
0
GPIO6/CLK
0: Corresponding GPIO is push-pull output during suspend if USE_SUSPEND = ’1’
1: Corresponding GPIO is open-drain output during suspend if USE_SUSPEND = ’1’
60 / 64
exar.com/XR21B1424
Rev 1C
 ▷