ModbusMiddleWare.c

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#include "ModbusMiddleWare.h"
#include "IoT_Supervisor.h"
#include <stdint.h>
#include <SI_EFM8BB1_Register_Enums.h>
 
code const uint8_t mmw_ct[eMMW_B_NUM][eMMW_CL_NUM] =
{
    {0, 0xEC,  0, 0},
    {0, 0xD8,  0, 0},
    {0, 0xB0,  1, 0},
    {0, 0x60,  4, 1},
    {1, 0xE5, 10, 3},
    {1, 0xCB, 22, 7}
};
 
uint8_t PETITMODBUS_DLY_TOP = 0;
uint8_t PETITMODBUS_SLAVE_ADDRESS = 0;
 
// Functions
void mmw_init(uint8_t sid, uint8_t baud)
{
    PETITMODBUS_SLAVE_ADDRESS = sid;
    if (baud == 0)
    {
        return;
    }
 
    // stop UART
    SCON0 &= ~SCON0_REN__BMASK & ~SCON0_MCE__BMASK;
    // stop timer 1
    TMOD = (TMOD & ~TMOD_T1M__FMASK) | TMOD_T1M__MODE3;
 
    // decode T1 clock source
    if (mmw_ct[baud - 1][eMMW_CL_T1_PRE] == 1)
    {
        // prescaler
        CKCON0 = (CKCON0 & ~CKCON0_T1M__BMASK) | CKCON0_T1M__PRESCALE;
    }
    else
    {
        // system clock
        CKCON0 = (CKCON0 & ~CKCON0_T1M__BMASK) | CKCON0_T1M__SYSCLK;
    }
 
    // set timer 1 mode to mode 2 (8-bit counter/timer with auto-reload)
    TMOD = (TMOD & ~TMOD_T1M__FMASK) | TMOD_T1M__MODE2;
 
    // set timer 1 current value and reload value
    TH1 = (mmw_ct[baud - 1][eMMW_CL_TH1] << TH1_TH1__SHIFT);
    TL1 = (mmw_ct[baud - 1][eMMW_CL_TH1] << TL1_TL1__SHIFT);
 
    // maybe this code will support parity values in the future, but the
    // efm8bb1 does not support parity.
 
    // enable UART, interestingly enough the MCE bit is just for
    // normal interrupts
    SCON0 |= SCON0_REN__RECEIVE_ENABLED | SCON0_MCE__MULTI_ENABLED;
 
    // software counter values
    PETITMODBUS_DLY_TOP = mmw_ct[baud - 1][eMMW_CL_PETIT_TOP];
    T0C_TOP = mmw_ct[baud - 1][eMMW_CL_TL0_TOP];
}