UART Serial Ports
21-2
Élan™SC520 Microcontroller User’s Manual
Figure 21-1
UART Block Diagram
21.3
SYSTEM DESIGN
UART 2 shares signals with the PIO31–PIO28 signals, as shown in Table 21-1. When
enabled, the multiplexed signals shown in Table 21-1 either disable or alter any other
function that uses the same pin.
Both UARTs can work with full modem control signals (SOUTx, SINx, CTSx, RTSx, DSRx,
DTRx, RINx, and DCDx) or with two wires only (SOUTx and SINx). If only two wires are
used, the unused input port pins can be left unconnected. (There are internal pullup resistors
on these signals.)
Table 21-1
UART Signals Shared with Other Interfaces
PIO
(Default)
Function
Interface
Function
Control Bit
Register
PIO31
RIN2
PIO31_FNC
PIO31–PIO16 Pin Function Select
(PIOPFS31_16) register (MMCR offset C22h)
PIO30
DCD2
PIO30_FNC
PIO29
DSR2
PIO29_FNC
PIO28
CTS2
PIO28_FNC
Transmitter
Interrupt
Configuration
rx_dma_req
uart_irq
tx_dma_req
SOUTx
SINx
clk_uart
RTSx
CTSx
DSRx
RINx
DTRx
DCDx
DMA Control
Prescaler
(18.432 MHz)
18.432 MHz
1.8432 MHz
From
clocks
To/from DMA
To PIC
Registers
out2
GP Bus
gptc
tx_dack
Élan™SC520 Microcontroller
Modem
Control
Baud
Generator
TX Hold Register
TX FIFO
TX shift register
Receiver
RX FIFO
RX Buffer Register
RX shift register
UART
rx_dack
Содержание Elan SC520
Страница 1: ...lan SC520 Microcontroller User s Manual Order 22004A...
Страница 4: ...iv lan SC520 Microcontroller User s Manual...
Страница 28: ...Introduction xxviii lan SC520 Microcontroller User s Manual...
Страница 42: ...Architectural Overview 1 14 lan SC520 Microcontroller User s Manual...
Страница 78: ...System Initialization 3 22 lan SC520 Microcontroller User s Manual...
Страница 108: ...Clock Generation and Control 5 10 lan SC520 Microcontroller User s Manual...
Страница 118: ...Reset Generation 6 10 lan SC520 Microcontroller User s Manual...
Страница 148: ...System Arbitration 8 24 lan SC520 Microcontroller User s Manual...
Страница 214: ...SDRAM Controller 10 36 lan SC520 Microcontroller User s Manual...
Страница 230: ...Write Buffer and Read Buffer 11 16 lan SC520 Microcontroller User s Manual...
Страница 288: ...GP Bus DMA Controller 14 22 lan SC520 Microcontroller User s Manual...
Страница 316: ...Programmable Interval Timer 16 8 lan SC520 Microcontroller User s Manual...
Страница 328: ...Software Timer 18 4 lan SC520 Microcontroller User s Manual...
Страница 346: ...Real Time Clock 20 12 lan SC520 Microcontroller User s Manual...
Страница 360: ...UART Serial Ports 21 14 lan SC520 Microcontroller User s Manual...
Страница 414: ...AMDebug Technology 26 8 lan SC520 Microcontroller User s Manual...