SPRUHM9H October 2014 – May 2024 TMS320F28075 , TMS320F28075-Q1 , TMS320F28076
There are three conditions that can cause the EMIF to generate an interrupt to the CPU. These conditions are:
The wait rise interrupt occurs when a rising edge is detected on EM1WAIT signal. This interrupt generation is not affected by the WPn bit in the asynchronous wait cycle configuration register (ASYNC_WCCR). The asynchronous time out interrupt condition occurs when the attached asynchronous device fails to deassert the EM1WAIT pin within the number of cycles defined by the MAX_EXT_WAIT bit in AWCC (this happens only in extended wait mode). The EMIF supports only linear incrementing and cache line wrap addressing modes . If an access request for an unsupported addressing mode is received, the EMIF sets the LT bit in the EMIF interrupt raw register (INT_RAW) and treats the request as a linear incrementing request.
Only when the interrupt is enabled by setting the appropriate bit (WR_MASK_SET/AT_MASK_SET/LT_MASK_SET) in the EMIF interrupt mask set register (INT_MSK_SET) to 1, is the interrupt sent to the CPU. Once enabled, the interrupt can be disabled by writing a 1 to the corresponding bit in the EMIF interrupt mask clear register (INT_MSK_CLR). The bit fields in both the INT_MSK_SET and INT_MSK_CLR can be used to indicate whether the interrupt is enabled. When the interrupt is enabled, the corresponding bit field in both the INT_MSK_SET and INT_MSK_CLR have a value of 1; when the interrupt is disabled, the corresponding bit field has a value of 0.
The EMIF interrupt raw register (INT_RAW) and the IF interrupt mask register (INT_MSK) indicate the status of each interrupt. The appropriate bit (WR/AT/LT) in INT_RAW is set when the interrupt condition occurs, whether or not the interrupt has been enabled. However, the appropriate bit (WR_MASKED/AT_MASKED/LT_MASKED) in INT_MSK is set only when the interrupt condition occurs and the interrupt is enabled. Writing a 1 to the bit in INT_RAW clears the INT_RAW bit as well as the corresponding bit in INT_MSK. Table 23-25 contains a brief summary of the interrupt status and control bit fields. See for complete details on the register fields.
Register Name | Bit Name | Description |
---|---|---|
EMIF interrupt raw register (INT_RAW) | WR | This bit is set when an rising edge on the EM1WAIT signal occurs. Writing a 1 clears the WR bit as well as the WR_MASKED bit in INT_MSK. |
AT | This bit is set when an asynchronous timeout occurs. Writing a 1 clears the AT bit as well as the AT_MASKED bit in INT_MSK. | |
LT | This bit is set when an unsupported addressing mode is used. Writing a 1 clears LT bit as well as the LT_MASKED bit in INT_MSK. | |
EMIF interrupt mask register (INT_MSK) | WR_MASKED | This bit is set only when a rising edge on the EM1WAIT signal occurs and the interrupt has been enabled by writing a 1 to the WR_MASK_SET bit in INT_MSK_SET. |
AT_MASKED | This bit is set only when an asynchronous timeout occurs and the interrupt has been enabled by writing a 1 to the AT_MASK_SET bit in INT_MSK_SET. | |
LT_MASKED | This bit is set only when line trap interrupt occurs and the interrupt has been enabled by writing a 1 to the LT_MASK_SET bit in INT_MSK_SET. | |
EMIF interrupt mask set register (INT_MSK_SET) | WR_MASK_SET | Writing a 1 to this bit enables the wait rise interrupt. |
AT_MASK_SET | Writing a 1 to this bit enables the asynchronous timeout interrupt. | |
LT_MASK_SET | Writing a 1 to this bit enables the line trap interrupt. | |
EMIF interrupt mask clear register (INT_MSK_CLR) | WR_MASK_CLR | Writing a 1 to this bit disables the wait rise interrupt. |
AT_MASK_CLR | Writing a 1 to this bit disables the asynchronous timeout interrupt. | |
LT_MASK_CLR | Writing a 1 to this bit disables the line trap interrupt. |