File : s-textio-stm32f7.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 STM32F7x, using USART6.
33 -- Serial interface is available via the arduino port of the board:
34 -- PIN D0 (PC7 GPIO): USART6_RX
35 -- PIN D1 (PC6 GPIO): USART6_TX
36
37 with Interfaces; use Interfaces;
38
39 with Interfaces.Bit_Types; use Interfaces.Bit_Types;
40 with Interfaces.STM32.RCC; use Interfaces.STM32.RCC;
41 with Interfaces.STM32.GPIO; use Interfaces.STM32.GPIO;
42 with Interfaces.STM32.USART; use Interfaces.STM32.USART;
43 with System.STM32; use System.STM32;
44 with System.BB.Parameters;
45
46 package body System.Text_IO is
47
48 Baudrate : constant := 115_200;
49 -- Bitrate to use
50
51 ----------------
52 -- Initialize --
53 ----------------
54
55 procedure Initialize is
56 use System.BB.Parameters;
57
58 APB_Clock : constant Positive := Positive (STM32.System_Clocks.PCLK2);
59 Int_Divider : constant Positive := (25 * APB_Clock) / (4 * Baudrate);
60 Frac_Divider : constant Natural := Int_Divider rem 100;
61
62 begin
63 Initialized := True;
64
65 RCC_Periph.APB2ENR.USART6EN := 1;
66 RCC_Periph.AHB1ENR.GPIOCEN := 1;
67
68 GPIOC_Periph.MODER.Arr (6 .. 7) := (Mode_AF, Mode_AF);
69 GPIOC_Periph.OSPEEDR.Arr (6 .. 7) := (Speed_50MHz, Speed_50MHz);
70 GPIOC_Periph.OTYPER.OT.Arr (6 .. 7) := (Push_Pull, Push_Pull);
71 GPIOC_Periph.PUPDR.Arr (6 .. 7) := (Pull_Up, Pull_Up);
72 GPIOC_Periph.AFRL.Arr (6 .. 7) := (AF_USART6, AF_USART6);
73
74 USART6_Periph.BRR :=
75 (DIV_Fraction => UInt4 (((Frac_Divider * 16 + 50) / 100) mod 16),
76 DIV_Mantissa => UInt12 (Int_Divider / 100),
77 others => <>);
78 USART6_Periph.CR1 :=
79 (UE => 1,
80 RE => 1,
81 TE => 1,
82 others => <>);
83 USART6_Periph.CR2 := (others => <>);
84 USART6_Periph.CR3 := (others => <>);
85 end Initialize;
86
87 -----------------
88 -- Is_Tx_Ready --
89 -----------------
90
91 function Is_Tx_Ready return Boolean is
92 (USART6_Periph.ISR.TC = 1);
93
94 -----------------
95 -- Is_Rx_Ready --
96 -----------------
97
98 function Is_Rx_Ready return Boolean is
99 (USART6_Periph.ISR.RXNE = 1);
100
101 ---------
102 -- Get --
103 ---------
104
105 function Get return Character is (Character'Val (USART6_Periph.RDR.RDR));
106
107 ---------
108 -- Put --
109 ---------
110
111 procedure Put (C : Character) is
112 begin
113 USART6_Periph.TDR.TDR := Character'Pos (C);
114 end Put;
115
116 ----------------------------
117 -- Use_Cr_Lf_For_New_Line --
118 ----------------------------
119
120 function Use_Cr_Lf_For_New_Line return Boolean is (True);
121
122 end System.Text_IO;