NXP Semiconductors LPC84x, Руководство пользователя

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UM11029 All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2017. All rights reserved.
User manual Rev. 1.0 — 16 June 2017 130 of 515
NXP Semiconductors
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Chapter 10: LPC84x Switch matrix (SWM)
Remark:
From all movable and fixed-pin functions, you can assign multiple functions to
the same pin but no more than one output or bidirectional function (see Figure 13 ). Use
the following guidelines when assigning pins:
•
You can connect one digital input signal on a pin to multiple internal inputs by
programming the same pin number in one or more PINASSIGN register.
Example:
You can enable the CLKIN input in the PINENABLE0 register on pin PIO0_1 and also
assign one ore more SCT inputs to pin PIO0_1 through the PINASSIGN registers to
feed the CLKIN into the SCT.
You can send the input on one pin to all SCT inputs to use as an SCT abort signal.
•
It is allowed to let one digital output function control one or more digital inputs by
programming the same pin number in the PINASSIGN register bit fields for the output
and inputs.
Example:
You can loop back the USART transmit output to the receive input by assigning the
same pin number to Un_RXD and Un_TXD.
• You cannot connect more than one output or bidirectional function to a pin.
•
When you assign any function to a pin through the switch matrix, the GPIO output
becomes disabled.
•
Enabling any analog fixed-pin function disables all digital functions on the same pin.
• Enabling any digital fixed-pin function disables all analog pin function on the same pin.
•
Digital and analog functions cannot share the same pin.
10.4.1 Movable functions
Table 178. Movable functions (assign to pins PIO0_0 to PIO0_31 and PIO1_0 to PIO1_21 through switch matrix)
Function name Type Description SWM Pin assign
register Reference
U0_TXD O Transmitter output for USART0. PINASSIGN0 Table 180
U0_RXD I Receiver input for USART0. PINASSIGN0 Table 180
U0_RTS O Request To Send output for USART0. PINASSIGN0 Table 180
U0_CTS I Clear To Send input for USART0. PINASSIGN0 Table 180
U0_SCLK I/O Serial clock input/output for USART0 in synchronous mode. PINASSIGN1 Table 181
U1_TXD O Transmitter output for USART1. PINASSIGN1 Table 181
U1_RXD I Receiver input for USART1. PINASSIGN1 Table 181
U1_RTS O Request To Send output for USART1. PINASSIGN1 Table 181
U1_CTS I Clear To Send input for USART1. PINASSIGN2 Table 182
U1_SCLK I/O Serial clock input/output for USART1 in synchronous mode. PINASSIGN2 Table 182
U2_TXD O Transmitter output for USART2. PINASSIGN2 Table 182
U2_RXD I Receiver input for USART2. PINASSIGN2 Table 182
U2_RTS O Request To Send output for USART1. PINASSIGN3 Table 183
U2_CTS I Clear To Send input for USART1. PINASSIGN3 Table 183
U2_SCLK I/O Serial clock input/output for USART1 in synchronous mode. PINASSIGN3 Table 183
SPI0_SCK I/O Serial clock for SPI0. PINASSIGN3 Table 183