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[/] [amber/] [trunk/] [hw/] [tests/] [uart_tx.S] - Rev 78
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/*****************************************************************
// //
// Amber 2 System UART Test //
// //
// This file is part of the Amber project //
// http://www.opencores.org/project,amber //
// //
// Description //
// Uses the tb_uart in loopback mode to verify the transmitted //
// data. //
// //
// Author(s): //
// - Conor Santifort, csantifort.amber@gmail.com //
// //
//////////////////////////////////////////////////////////////////
// //
// Copyright (C) 2010 Authors and OPENCORES.ORG //
// //
// This source file may be used and distributed without //
// restriction provided that this copyright statement is not //
// removed from the file and that any derivative work contains //
// the original copyright notice and the associated disclaimer. //
// //
// This source file is free software; you can redistribute it //
// and/or modify it under the terms of the GNU Lesser General //
// Public License as published by the Free Software Foundation; //
// either version 2.1 of the License, or (at your option) any //
// later version. //
// //
// This source is distributed in the hope that it will be //
// useful, but WITHOUT ANY WARRANTY; without even the implied //
// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR //
// PURPOSE. See the GNU Lesser General Public License for more //
// details. //
// //
// You should have received a copy of the GNU Lesser General //
// Public License along with this source; if not, download it //
// from http://www.opencores.org/lgpl.shtml //
// //
*****************************************************************/
#include "amber_registers.h"
.section .text
.globl main
main:
@ Put test_uart into loopback mode, and enable transmit
ldr r0, AdrTEST_UART_CONTROL
mov r1, #0x3
str r1, [r0]
@ Write to and read back from UART0 registers
ldr r4, AdrUART0DR
ldr r5, =Message
ldr r9, =Message
ldr r7, =EndMessage
1: bl wait_tx_full
ldrb r6, [r5], #1
@ transmit byte from test_uart
str r6, [r4]
bl uart_rx_check
@ keep doing this until get to the end of the message
cmp r5, r7
bne 1b
@ The complete message has now been transmitted
@ but some bytes are still en route
@ check the last few bytes received
bl uart_rx_check
@ check that all bytes were received
add r9, r9, #2
cmp r9, r7
movne r10, #100
bne testfail
b testpass
@ -------------------------------------------
wait_tx_full:
@ with timeout loop of 0x400
ldr r0, AdrUART0FR
mov r2, #0x400
1: subs r2, r2, #1
moveq r10, #100
beq testfail
ldr r1, [r0]
ands r1, r1, #0x20
bne 1b
mov pc, lr
uart_rx_check:
ldr r2, AdrUART0DR @ rx/tx byte
ldr r3, AdrUART0FR @ flags
@ if rx fifo empty flag == 1, return without doing anything
1: ldr r0, [r3]
ands r0, r0, #0x10
movne pc, lr
ldrb r0, [r2] @ uart rx byte
ldrb r1, [r9], #1 @ transmitted text
cmp r0, r1
movne r10, #20
bne testfail
@ check if there are more bytes in rx buffer
b 1b
testfail:
ldr r11, AdrTestStatus
str r10, [r11]
b testfail
testpass:
ldr r11, AdrTestStatus
mov r10, #17
str r10, [r11]
b testpass
@ ------------------------------------------
@ ------------------------------------------
/* Write 17 to this address to generate a Test Passed message */
AdrTestStatus: .word ADR_AMBER_TEST_STATUS
AdrTEST_UART_CONTROL: .word ADR_AMBER_TEST_UART_CONTROL
AdrUART0DR: .word ADR_AMBER_UART0_DR
AdrUART0FR: .word ADR_AMBER_UART0_FR
Message: .ascii "\nThis message is brought to you by UART0\nThats all folks\n"
EndMessage: .word 0
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