File : s-textio-stm32f4.adb
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT RUN-TIME COMPONENTS --
4 -- --
5 -- S Y S T E M . T E X T _ I O --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 1992-2016, Free Software Foundation, Inc. --
10 -- --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. --
17 -- --
18 -- --
19 -- --
20 -- --
21 -- --
22 -- You should have received a copy of the GNU General Public License and --
23 -- a copy of the GCC Runtime Library Exception along with this program; --
24 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
25 -- <http://www.gnu.org/licenses/>. --
26 -- --
27 -- GNAT was originally developed by the GNAT team at New York University. --
28 -- Extensive contributions were provided by Ada Core Technologies Inc. --
29 -- --
30 ------------------------------------------------------------------------------
31
32 -- Minimal version of Text_IO body for use on STM32F4xxx, using USART1
33
34 with Interfaces; use Interfaces;
35
36 with Interfaces.Bit_Types; use Interfaces.Bit_Types;
37 with Interfaces.STM32.RCC; use Interfaces.STM32.RCC;
38 with Interfaces.STM32.GPIO; use Interfaces.STM32.GPIO;
39 with Interfaces.STM32.USART; use Interfaces.STM32.USART;
40 with System.STM32; use System.STM32;
41 with System.BB.Parameters;
42
43 package body System.Text_IO is
44
45 Baudrate : constant := 115_200;
46 -- Bitrate to use
47
48 ----------------
49 -- Initialize --
50 ----------------
51
52 procedure Initialize is
53 use System.BB.Parameters;
54
55 APB_Clock : constant Positive := Positive (STM32.System_Clocks.PCLK2);
56 Int_Divider : constant Positive := (25 * APB_Clock) / (4 * Baudrate);
57 Frac_Divider : constant Natural := Int_Divider rem 100;
58
59 begin
60 Initialized := True;
61
62 RCC_Periph.APB2ENR.USART1EN := 1;
63 RCC_Periph.AHB1ENR.GPIOBEN := 1;
64
65 GPIOB_Periph.MODER.Arr (6 .. 7) := (Mode_AF, Mode_AF);
66 GPIOB_Periph.OSPEEDR.Arr (6 .. 7) := (Speed_50MHz, Speed_50MHz);
67 GPIOB_Periph.OTYPER.OT.Arr (6 .. 7) := (Push_Pull, Push_Pull);
68 GPIOB_Periph.PUPDR.Arr (6 .. 7) := (Pull_Up, Pull_Up);
69 GPIOB_Periph.AFRL.Arr (6 .. 7) := (AF_USART1, AF_USART1);
70
71 USART1_Periph.BRR :=
72 (DIV_Fraction => UInt4 (((Frac_Divider * 16 + 50) / 100) mod 16),
73 DIV_Mantissa => UInt12 (Int_Divider / 100),
74 others => <>);
75 USART1_Periph.CR1 :=
76 (UE => 1,
77 RE => 1,
78 TE => 1,
79 others => <>);
80 USART1_Periph.CR2 := (others => <>);
81 USART1_Periph.CR3 := (others => <>);
82 end Initialize;
83
84 -----------------
85 -- Is_Tx_Ready --
86 -----------------
87
88 function Is_Tx_Ready return Boolean is
89 (USART1_Periph.SR.TC = 1);
90
91 -----------------
92 -- Is_Rx_Ready --
93 -----------------
94
95 function Is_Rx_Ready return Boolean is
96 (USART1_Periph.SR.RXNE = 1);
97
98 ---------
99 -- Get --
100 ---------
101
102 function Get return Character is (Character'Val (USART1_Periph.DR.DR));
103
104 ---------
105 -- Put --
106 ---------
107
108 procedure Put (C : Character) is
109 begin
110 USART1_Periph.DR.DR := Character'Pos (C);
111 end Put;
112
113 ----------------------------
114 -- Use_Cr_Lf_For_New_Line --
115 ----------------------------
116
117 function Use_Cr_Lf_For_New_Line return Boolean is (True);
118 end System.Text_IO;