Support Board: BK7236

UART

Project Overview

This project is used for demonstrating [peripheral URAT](https://docs.bekencorp.com/armino/bk7236/en/latest/developer-guide/peripheral/bk_uart.html). The security function of BK7236 is still under development and improvement, please note the following restrictions

UART (Universal Asynchronous Receiver and Transmitter), It is used to realize full duplex or half duplex data exchange between different devices.

Hardware Requirements

The figure above shows the UART serial port TTL level hardware connection, where:

TXD：For sending data, it should be connected to RXD pin of the receiving device

RXD：For receiving data, it should be connected to the TXD pin of the transmitting device

GND：Provide the same reference level for both parties

UART Config

In order to use UART for data transmission, the following parameters need to be configured：

Baud rate：The number of bits transmitted per second, generally 9600, 19200, 115200, etc. call function bk_uart_set_baud_rate()

Data bits：There can be 5, 6, 7 or 8 bits of data. Generally, we transmit data by byte (8 bits). The sender changes the status (high level or low level) of the data line bit by bit to send them. When transmitting data, the lowest bit is transmitted first, and the highest bit is transmitted last.call function bk_uart_set_data_bits()

Check bit：It is used to verify the correctness of data transmission. It can only detect errors, not correct them. call function bk_uart_set_parity()

Stop bit：It is used to indicate that the current data transmission is completed, and the logic level is “1”. call function bk_uart_set_stop_bits()

UART Application Scenario

At present, UART supports three different application modes：

Use the default UART interrupt processing flow： The default ‘bk_uart_write_bytes()/bk_uart_read_bytes()’ is used to process UART receiving and sending. The receiving and sending channel is described in the UART receiving channel section. Generally, this method can meet the needs of most applications.
Use the default UART interrupt processing flow and register the user callback： The only difference from the first method is that the user’s registered callback will be called after the UART interrupt is generated.
UART interrupt processing is completely implemented by the application itself： When the default UART interrupt processing flow cannot meet the application requirements, such as the UART of the application is implemented by a third-party code, you can use ‘bk_interrupt_Register(xx, isr, arg)’ replaces the default UART interrupt handler. At this time, the receiving and sending process is completely implemented by the application.

Case Build

Enter the following command in the Armino root directory to compile:

> make bk7236 PROJECT=examples/peripherals/uart

For preparations such as toolchain installation, please refer to [Quick Start](https://docs.bekencorp.com/armino/bk7236/en/latest/get-started/index.html).

Flash all-app.bin

Burn Armino/build/secureboot/bk7236/all-app.bin to the board using BKFIL.

Running and Output

Case - uart log

uart log

os:I(0):mem_type start    end      size
os:I(0):-------- -------- -------- --------
os:I(0):itcm     0x0      0x3c58   15448
os:I(0):dtcm     0x20000000 0x20001908 6408
os:I(0):ram      0x28000000 0x2807ebf8 519160
os:I(0):non_heap 0x28000000 0x2800fca8 64680
os:I(0):iram     0x28000000 0x28000814 2068
os:I(0):data     0x28000814 0x280011b0 2460
os:I(0):bss      0x280011c0 0x2800fca8 60136
os:I(0):non_cache 0x2800fca8 0x2800fca8 0
os:I(0):heap     0x2800fca8 0x2807ebf8 454480
os:I(0):psram    0x60700000 0x60780000 524288
flash:I(0):id=0xc84016
flash:I(0):write status reg:38, status_reg_size:1
I(0):ate enabled is 1
I(0):driver_init end
init:I(0):reason - deep sleep gpio
init:I(0):regs - 3, 3, 0
init:I(0):armino rev:
init:I(0):armino soc id:53434647_72360001
init:I(0):trng enable
os:I(0):prvHeapInit-psram start addr:0x60700000, size:524288
mailbox:I(0):mailbox_config
mailbox:I(0):bk_mailbox_recv_callback_register
mailbox:I(0):bk_mailbox_recv_callback_register
init:I(0):Intialize random stack guard.
os:I(0):create main, tcb=28011898, stack=[28010870-28011870:4096], prio=5
I(0):start user app thread.
os:I(0):create app, tcb=28012940, stack=[28011918-28012918:4096], prio=2
os:I(0):os time(0ms).
os:I(0):base aon rtc time: 0:46
os:I(0):create IDLE, t`b=20000330, stack=[2000038c-2000098c:1536], prio=0
os:I(0):create Tmr Svc, tcb=2000098c, stack=[200009e8-20000fe8:1536], prio=5
uart_exa:I(0):uart send data:
uart_exa:I(2):data[0]=0x0
uart_exa:I(4):data[1]=0x1
uart_exa:I(6):data[2]=0x2
uart_exa:I(8):data[3]=0x3
uart_exa:I(10):data[4]=0x4
uart_exa:I(12):data[5]=0x5
uart_exa:I(14):data[6]=0x6
uart_exa:I(16):data[7]=0x7
uart_exa:I(18):data[8]=0x8
uart_exa:I(20):data[9]=0x9
uart_exa:I(22):data[10]=0xa
uart_exa:I(24):data[11]=0xb
uart_exa:I(26):data[12]=0xc
uart_exa:I(28):data[13]=0xd
uart_exa:I(30):data[14]=0xe
uart_exa:I(32):data[15]=0xf
uart_exa:I(34):data[16]=0x10
uart_exa:I(36):data[17]=0x11
uart_exa:I(38):data[18]=0x12
uart_exa:I(40):data[19]=0x13
uart_exa:I(42):data[20]=0x14
uart_exa:I(44):data[21]=0x15
uart_exa:I(46):data[22]=0x16
uart_exa:I(48):data[23]=0x17
uart_exa:I(50):data[24]=0x18
uart_exa:I(52):data[25]=0x19
uart_exa:I(54):data[26]=0x1a
uart_exa:I(56):data[27]=0x1b
uart_exa:I(58):data[28]=0x1c
uart_exa:I(60):data[29]=0x1d
uart_exa:I(62):data[30]=0x1e
uart_exa:I(64):data[31]=0x1f
uart_exa:I(66):data[32]=0x20
uart_exa:I(68):data[33]=0x21
uart_exa:I(70):data[34]=0x22
uart_exa:I(72):data[35]=0x23
uart_exa:I(74):data[36]=0x24
uart_exa:I(76):data[37]=0x25
uart_exa:I(78):data[38]=0x26
uart_exa:I(80):data[39]=0x27
uart_exa:I(82):data[40]=0x28
uart_exa:I(84):data[41]=0x29
uart_exa:I(86):data[42]=0x2a
uart_exa:I(88):data[43]=0x2b
uart_exa:I(90):data[44]=0x2c
uart_exa:I(92):data[45]=0x2d
uart_exa:I(94):data[46]=0x2e
uart_exa:I(96):data[47]=0x2f
uart_exa:I(98):data[48]=0x30
uart_exa:I(100):data[49]=0x31
uart_exa:I(102):data[50]=0x32
uart_exa:I(104):data[51]=0x33
uart_exa:I(106):data[52]=0x34
uart_exa:I(108):data[53]=0x35
uart_exa:I(110):data[54]=0x36
uart_exa:I(112):data[55]=0x37
uart_exa:I(114):data[56]=0x38
uart_exa:I(116):data[57]=0x39
uart_exa:I(118):data[58]=0x3a
uart_exa:I(120):data[59]=0x3b
uart_exa:I(122):data[60]=0x3c
uart_exa:I(124):data[61]=0x3d
uart_exa:I(126):data[62]=0x3e
uart_exa:I(128):data[63]=0x3f
uart_exa:I(130):data[64]=0x40
uart_exa:I(132):data[65]=0x41
uart_exa:I(134):data[66]=0x42
uart_exa:I(136):data[67]=0x43
uart_exa:I(138):data[68]=0x44
uart_exa:I(140):data[69]=0x45
uart_exa:I(142):data[70]=0x46
uart_exa:I(144):data[71]=0x47
uart_exa:I(146):data[72]=0x48
uart_exa:I(148):data[73]=0x49
uart_exa:I(150):data[74]=0x4a
uart_exa:I(152):data[75]=0x4b
uart_exa:I(154):data[76]=0x4c
uart_exa:I(156):data[77]=0x4d
uart_exa:I(158):data[78]=0x4e
uart_exa:I(160):data[79]=0x4f
uart_exa:I(162):data[80]=0x50
uart_exa:I(164):data[81]=0x51
uart_exa:I(166):data[82]=0x52
uart_exa:I(168):data[83]=0x53
uart_exa:I(170):data[84]=0x54
uart_exa:I(172):data[85]=0x55
uart_exa:I(176):data[86]=0x56
uart_exa:I(178):data[87]=0x57
uart_exa:I(180):data[88]=0x58
uart_exa:I(182):data[89]=0x59
uart_exa:I(184):data[90]=0x5a
uart_exa:I(186):data[91]=0x5b
uart_exa:I(188):data[92]=0x5c
uart_exa:I(190):data[93]=0x5d
uart_exa:I(192):data[94]=0x5e
uart_exa:I(194):data[95]=0x5f
uart_exa:I(196):data[96]=0x60
uart_exa:I(198):data[97]=0x61
uart_exa:I(200):data[98]=0x62
uart_exa:I(202):data[99]=0x63
uart_exa:I(204):data[100]=0x64
uart_exa:I(206):data[101]=0x65
uart_exa:I(208):data[102]=0x66
uart_exa:I(210):data[103]=0x67
uart_exa:I(212):data[104]=0x68
uart_exa:I(214):data[105]=0x69
uart_exa:I(216):data[106]=0x6a
uart_exa:I(218):data[107]=0x6b
uart_exa:I(220):data[108]=0x6c
uart_exa:I(222):data[109]=0x6d
uart_exa:I(224):data[110]=0x6e
uart_exa:I(226):data[111]=0x6f
uart_exa:I(228):data[112]=0x70
uart_exa:I(230):data[113]=0x71
uart_exa:I(232):data[114]=0x72
uart_exa:I(234):data[115]=0x73
uart_exa:I(236):data[116]=0x74
uart_exa:I(238):data[117]=0x75
uart_exa:I(240):data[118]=0x76
uart_exa:I(242):data[119]=0x77
uart_exa:I(244):data[120]=0x78
uart_exa:I(246):data[121]=0x79
uart_exa:I(248):data[122]=0x7a
uart_exa:I(250):data[123]=0x7b
uart_exa:I(252):data[124]=0x7c
uart_exa:I(254):data[125]=0x7d
uart_exa:I(256):data[126]=0x7e
uart_exa:I(258):data[127]=0x7f
\0
  

!”#$%&’()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[]^_`abcdefghijklmnopqrstuvwxyz{|}~uart_exa:I(270):uart recv data:: uart_exa:I(272):data[0]=0xf0 I(274):ATE enabled = 1