====== GPIO over CPLD ======

Each of the 4 GPIO ports contains 8 ouput and 8 input pins. The ports are not as fast as the integrated [[stm32:peripherals:gpio|GPIO ports]] of the microcontroller. \\ \\

> {{ctboard:ctboard_mode_1.svg?48px }} Please make sure the CT Board is in the correct mode.
> Supported [[ctboard:mode_switch|mode]]: **1**
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===== Registers =====

==== Input ====

\\ {{ ctboard_gpio_pinout.svg?300em}} 
   {{ctboard_gpio_input_reg.svg}} \\ \\

==== Output ====

The registers are read / write.

\\ {{ctboard_gpio_output_reg.svg}} \\ \\

===== Diagram =====

\\ {{ctboard_gpio_cpld.svg}} \\ \\

===== Programming Example =====

The code snippets below show how to use the GPIO.

<code c>
#include "reg_ctboard.h"

uint8_t data_byte = CT_GPIO->IN.BYTE.P1;              /* Read byte from P1. */
uint16_t data_hword = CT_GPIO->IN.HWORD.P2_1;         /* Read half word from P1 and P2. */
uint32_t data_word = CT_GPIO->IN.WORD;                /* Read word from all ports (P1..4). */

CT_GPIO->OUT.BYTE.P3 = (uint8_t) data_byte;           /* Write byte of data to P3. */
CT_GPIO->OUT.HWORD.P4_3 = (uint16_t) data_halfword;   /* Write halfword of data to P3..4 */
CT_GPIO->OUT.WORD = (uint32_t) data_word;             /* Write word of data to all ports (P1..4). */
</code>
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<code asm>
ADDR_GPIO_IN    EQU      0x60000410
ADDR_GPIO_OUT   EQU      0x60000400
                
                LDR      r0, =ADDR_GPIO_IN
                LDRB     r1, [r0, #0]                 ; Read byte from P1.
                LDRH     r1, [r0, #0]                 ; Read half word from P1 and P2.
                LDR      r1, [r0, #0]                 ; Read word from all ports (P1..4).
                
                LDR      r0, =ADDR_GPIO_OUT
                STRB     r1, [r0, #2]                 ; Write byte of data to P3.
                STRH     r1, [r0, #2]                 ; Write halfword of data to P3..4.
                STR      r1, [r0, #0]                 ; Write word of data to all ports (P1..4).
</code>
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