/*****************************************************************************
* FUNCTION: ChipReset
*
* RETURNS: N/A
*
* PARAMS:
* N/A
*
*
* NOTES: Performs the necessary SPI operations to cause the MRF24WB0M to reset.
* This function also implements a delay so that it will not return until
* the WiFi device is ready to receive messages again. The delay time will
* vary depending on the amount of code that must be loaded from serial
* flash.
*****************************************************************************/
static void ChipReset(void)
{
UINT16 value;
UINT32 timeoutPeriod;
UINT32 startTickCount;
timeoutPeriod = TICKS_PER_SECOND; /* 1000 ms */
/* needed for Microchip PICTail (chip enable active low) */
WF_SetCE_N(WF_LOW); /* set low to enable regulator */
/* Configure reset pin */
WF_SetRST_N(WF_HIGH);
/* Let SPI lines settle before first SPI transaction */
DelayMs(1);
/* clear the power bit to disable low power mode on the MRF24WB0M */
Write16BitWFRegister(WF_PSPOLL_H_REG, 0x0000);
/* Set HOST_RESET bit in register to put device in reset */
Write16BitWFRegister(WF_HOST_RESET_REG, Read16BitWFRegister(WF_HOST_RESET_REG) | WF_HOST_RESET_MASK);
/* Clear HOST_RESET bit in register to take device out of reset */
Write16BitWFRegister(WF_HOST_RESET_REG, Read16BitWFRegister(WF_HOST_RESET_REG) & ~WF_HOST_RESET_MASK);
/* after reset is started poll register to determine when HW reset has completed */
startTickCount = (UINT32)TickGet();
do
{
Write16BitWFRegister(WF_INDEX_ADDR_REG, WF_HW_STATUS_REG);
value = Read16BitWFRegister(WF_INDEX_DATA_REG);
if (TickGet() - startTickCount >= timeoutPeriod)
{
WF_ASSERT(FALSE);
}
} while ( (value & WF_HW_STATUS_NOT_IN_RESET_MASK) == 0);
/* if SPI not connected will read all 1's */
WF_ASSERT(value != 0xffff);
/* now that chip has come out of HW reset, poll the FIFO byte count register */
/* which will be set to a non-zero value when the MRF24WB0M initialization is */
/* complete. */
startTickCount = (UINT32)TickGet();
do
{
value = Read16BitWFRegister(WF_HOST_WFIFO_BCNT0_REG);
if (TickGet() - startTickCount >= timeoutPeriod)
{
WF_ASSERT(FALSE);
}
} while (value == 0);
}
/*****************************************************************************
* FUNCTION: WFHardwareInit
*
* RETURNS: error code
*
* PARAMS: None
*
* NOTES: Initializes CPU Host hardware interfaces (SPI, External Interrupt).
* Also resets the MRF24W.
*****************************************************************************/
void WFHardwareInit(void)
{
UINT8 mask8;
UINT16 mask16;
g_MgmtReadMsgReady = FALSE;
g_ExIntNeedsServicing = FALSE;
RawMoveState.rawInterrupt = 0;
RawMoveState.waitingForRawMoveCompleteInterrupt = FALSE; /* not waiting for RAW move complete */
/* needed for Microchip PICTail (chip enable active low) */
WF_SetCE_N(WF_LOW); /* set low to enable regulator */
/* initialize the SPI interface */
WF_SpiInit();
ResetPll(); // needed until PLL fix made in A2 silicon
/* Reset the MRF24W (using SPI bus to write/read MRF24W registers */
ChipReset();
/* disable the interrupts gated by the 16-bit host int register */
HostInterrupt2RegInit(WF_HOST_2_INT_MASK_ALL_INT, (UINT16)WF_INT_DISABLE);
/* disable the interrupts gated the by main 8-bit host int register */
HostInterruptRegInit(WF_HOST_INT_MASK_ALL_INT, WF_INT_DISABLE);
/* Initialize the External Interrupt for the MRF24W allowing the MRF24W to interrupt */
/* the Host from this point forward. */
WF_EintInit();
WF_EintEnable();
/* enable the following MRF24W interrupts in the INT1 8-bit register */
mask8 = (WF_HOST_INT_MASK_FIFO_1_THRESHOLD | /* Mgmt Rx Msg interrupt */
WF_HOST_INT_MASK_FIFO_0_THRESHOLD | /* Data Rx Msg interrupt */
WF_HOST_INT_MASK_RAW_0_INT_0 | /* RAW0 Move Complete (Data Rx) interrupt */
WF_HOST_INT_MASK_RAW_1_INT_0 | /* RAW1 Move Complete (Data Tx) interrupt */
WF_HOST_INT_MASK_INT2); /* Interrupt 2 interrupt */
HostInterruptRegInit(mask8, WF_INT_ENABLE);
/* enable the following MRF24W interrupts in the INT2 16-bit register */
mask16 = (WF_HOST_INT_MASK_RAW_2_INT_0 | /* RAW2 Move Complete (Mgmt Rx) interrupt */
WF_HOST_INT_MASK_RAW_3_INT_0 | /* RAW3 Move Complete (Mgmt Tx) interrupt */
WF_HOST_INT_MASK_RAW_4_INT_0 | /* RAW4 Move Complete (Scratch) interrupt */
WF_HOST_INT_MASK_RAW_5_INT_0 | /* RAW5 Move Complete (Scratch) interrupt */
WF_HOST_INT_MASK_MAIL_BOX_0_WRT);
HostInterrupt2RegInit(mask16, WF_INT_ENABLE);
/* Disable PS-Poll mode */
WFConfigureLowPowerMode(WF_LOW_POWER_MODE_OFF);
}
/*******************************************************************************
Function:
void WF_HibernateEnable()
Summary:
Puts the MRF24W into hibernate mode.
Description:
Enables Hibernate mode on the MRF24W, which effectively turns off the
device for maximum power savings.
MRF24W state is not maintained when it transitions to hibernate mode.
To remove the MRF24W from hibernate mode call WF_Init().
Precondition:
MACInit must be called first.
Parameters:
None.
Returns:
None.
Remarks:
Note that because the MRF24W does not save state, there will be a
disconnect between the TCP/IP stack and the MRF24B0M state. If it is
desired by the application to use hibernate, additional measures must be
taken to save application state. Then the host should be reset. This will
ensure a clean connection between MRF24W and TCP/IP stack
Future versions of the stack might have the ability to save stack context
as well, ensuring a clean wake up for the MRF24W without needing a host
reset.
*****************************************************************************/
void WF_HibernateEnable()
{
WF_SetCE_N(WF_HIGH); /* set XCEN33 pin high, which puts MRF24W in hibernate mode */
/* SetPowerSaveState(WF_PS_HIBERNATE); */
}
/*******************************************************************************
Function:
void DRV_WIFI_HibernateEnable(void)
Summary:
Puts the MRF24WG into hibernate mode.
Description:
Enables Hibernate mode on the MRF24W, which effectively turns off the
device for maximum power savings.
MRF24W state is not maintained when it transitions to hibernate mode.
Parameters:
None.
Returns:
None.
Remarks:
None
*****************************************************************************/
void DRV_WIFI_HibernateEnable()
{
WF_SetCE_N(WIFI_PIN_HIGH); /* set XCEN33 pin high, which puts MRF24W in hibernate mode */
g_hibernateMode = true;
}
/*****************************************************************************
* FUNCTION: WFHardwareInit
*
* RETURNS: error code
*
* PARAMS: None
*
* NOTES: Initializes CPU Host hardware interfaces (SPI, External Interrupt).
* Also resets the MRF24W.
*****************************************************************************/
void WFHardwareInit(void)
{
UINT8 mask8;
UINT16 mask16;
g_MgmtReadMsgReady = FALSE;
g_ExIntNeedsServicing = FALSE;
RawMoveState.rawInterrupt = 0;
RawMoveState.waitingForRawMoveCompleteInterrupt = FALSE; /* not waiting for RAW move complete */
/* initialize the SPI interface */
WF_SpiInit();
#if defined(__Digilent_Build__)
WF_SetRST_N(WF_LOW); // put module into reset; should already be there.
// we have taken out the next 3 lines as MarkW says we do not need to toggle HIB to competely reset the part.
// WF_SetCE_N(WF_HIGH); // disable module, turn off regulators
// DelayMs(200); // 200ms to allow decoupling caps to discharge, between the 70uF in the MRF , this can take some time.
// WF_SetCE_N(WF_LOW); // enable module, turn on regulators; careful this has an inrush that can drag the Power supply below min. if the MRF is not decoupled well enough.
DelayMs(2); // Spec says at least 1ms to let the regulators settle, leave this here to ensure timing from board powerup.
WF_SetRST_N(WF_HIGH); // take module out of of reset
DelayMs(5); // Per MarkW’s email, leave 5ms here before accessing the SPI port
#else
/* Toggle the module into and then out of hibernate */
WF_SetCE_N(WF_HIGH); /* disable module */
WF_SetCE_N(WF_LOW); /* enable module */
/* Toggle the module into and out of reset */
WF_SetRST_N(WF_LOW); // put module into reset
WF_SetRST_N(WF_HIGH); // take module out of of reset
#endif
/* Silicon work-around -- needed for A1 silicon to initialize PLL values correctly */
ResetPll();
/* Soft reset the MRF24W (using SPI bus to write/read MRF24W registers */
ChipReset();
/* disable the interrupts gated by the 16-bit host int register */
HostInterrupt2RegInit(WF_HOST_2_INT_MASK_ALL_INT, (UINT16)WF_INT_DISABLE);
/* disable the interrupts gated the by main 8-bit host int register */
HostInterruptRegInit(WF_HOST_INT_MASK_ALL_INT, WF_INT_DISABLE);
/* Initialize the External Interrupt for the MRF24W allowing the MRF24W to interrupt */
/* the Host from this point forward. */
WF_EintInit();
WF_EintEnable();
/* enable the following MRF24W interrupts in the INT1 8-bit register */
mask8 = (WF_HOST_INT_MASK_FIFO_1_THRESHOLD | /* Mgmt Rx Msg interrupt */
WF_HOST_INT_MASK_FIFO_0_THRESHOLD | /* Data Rx Msg interrupt */
WF_HOST_INT_MASK_RAW_0_INT_0 | /* RAW0 Move Complete (Data Rx) interrupt */
WF_HOST_INT_MASK_RAW_1_INT_0 | /* RAW1 Move Complete (Data Tx) interrupt */
WF_HOST_INT_MASK_INT2); /* Interrupt 2 interrupt */
HostInterruptRegInit(mask8, WF_INT_ENABLE);
/* enable the following MRF24W interrupts in the INT2 16-bit register */
mask16 = (WF_HOST_INT_MASK_RAW_2_INT_0 | /* RAW2 Move Complete (Mgmt Rx) interrupt */
WF_HOST_INT_MASK_RAW_3_INT_0 | /* RAW3 Move Complete (Mgmt Tx) interrupt */
WF_HOST_INT_MASK_RAW_4_INT_0 | /* RAW4 Move Complete (Scratch) interrupt */
WF_HOST_INT_MASK_RAW_5_INT_0 | /* RAW5 Move Complete (Scratch) interrupt */
WF_HOST_INT_MASK_MAIL_BOX_0_WRT);
HostInterrupt2RegInit(mask16, WF_INT_ENABLE);
/* Disable PS-Poll mode */
WFConfigureLowPowerMode(WF_LOW_POWER_MODE_OFF);
}
