MAX14830 Datasheet, PDF (17/68 Pages) Maxim Integrated Products – Quad Serial UART with 128-Word FIFOs

MAX14830
Quad Serial UART with 128-Word FIFOs
Pin Description (continued)
PIN
NAME
FUNCTION
General-Purpose Input/Output 9. GPIO9 is user-programmable as an input or output (push-pull or open
28
GPIO9 drain) or external event interrupt source. GPIO9 has a weak pulldown resistor to ground. GPIO9 is the
TIMER output when bit 7 of the TIMER2 register is set to 1.
29
GPIO10
General-Purpose Input/Output 10. GPIO10 is user-programmable as an input or output (push-pull or
open drain) or external event interrupt source. GPIO10 has a weak pulldown resistor to ground.
30
GPIO11
General-Purpose Input/Output 11. GPIO11 is user-programmable as an input or output (push-pull or
open drain) or external event interrupt source. GPIO11 has a weak pulldown resistor to ground.
Active-Low Request-to-Send Output for UART2. RTS2 can be set high or low by programming the LCR
31
RTS2 register. RTS2 is the UART system clock/fractional divider output when bit 7 of the CLKSource register
is set to 1.
32
CTS2 Active-Low Clear-to-Send Input for UART2. CTS2 is a flow control status input.
33
RX2 Serial Receiving Data Input for UART2. RX2 has a weak pullup to VEXT.
34
TX2 Serial Transmitting Data Output for UART2
General-Purpose Input/Output 12. GPIO12 is user-programmable as an input or output (push-pull
35
GPIO12
or open drain) or external event interrupt source. GPIO12 has a weak pulldown resistor to ground.
GPIO12 is the reference clock output when bit 7 of the TxSynch register is set to 1 (see the UART
Clock to GPIO section for more information).
General-Purpose Input/Output 13. GPIO13 is user-programmable as an input or output (push-pull
36
GPIO13 or open drain) or external event interrupt source. GPIO13 has a weak pulldown resistor to ground.
GPIO13 is the TIMER output if bit 7 of the TIMER2 register is set to 1.
37
GPIO14
General-Purpose Input/Output 14. GPIO14 is user-programmable as an input or output (push-pull or
open drain) or external event interrupt source. GPIO14 has a weak pulldown resistor to ground.
38
GPIO15
General-Purpose Input/Output 15. GPIO15 is user-programmable as an input or output (push-pull or
open drain) or external event interrupt source. GPIO15 has a weak pulldown resistor to ground.
Active-Low Request-to-Send Output for UART3. RTS3 can be set high or low by programming the LCR
39
RTS3 register. RTS3 is the UART system clock/fractional divider output when bit 7 of the CLKSource register
is set to 1.
40
CTS3 Active-Low Clear-to-Send Input for UART3. CTS3 is a flow control status input.
41
RX3 Serial Receiving Data Input for UART3. RX3 has a weak pullup to VEXT.
42
TX3 Serial Transmitting Data Output for UART3
43
VEXT
Transceiver Interface Level Supply. VEXT powers the internal logic-level translators for RX_, TX_, RTS_,
CTS_, and GPIO_. Bypass VEXT with a 0.1FF ceramic capacitor to DGND.
44
XOUT
Crystal Output. When using an external crystal, connect one end of the crystal to XOUT and the other
to XIN. When using an external clock source, leave XOUT unconnected.
45
XIN
Crystal/Clock Input. When using an external crystal, connect one end of the crystal to XIN and the
other one to XOUT. When using an external clock source, drive XIN with the external clock.
46
AGND Analog Ground
47
VA
Analog Supply. VA powers the PLL, and the internal LDO. Bypass VA with a 0.1FF ceramic capacitor to
AGND.
48
V18
Internal 1.8V LDO Output and 1.8V Logic Supply Input. Bypass V18 with a 1FF ceramic capacitor to
DGND.
—
EP
Exposed Paddle. Connect EP to AGND. Do not use EP as the main AGND connection.
Maxim Integrated
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