SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
There is a DMA_CROSSBAR module in the device, which is controlled by registers in the CTRL_MODULE_CORE submodule. The DMA_CROSSBAR is able to map any of its input signals to any of its outputs. This module is associated with the device DMA request source signals. The DREQs from all the device modules are connected to the DMA_CROSSBAR inputs. Each DREQ signal is connected only to one DMA cross-bar input. Each output of the DMA_CROSSBAR module is connected only to one input line of the device DMA modules. The DMAs associated with the DMA_CROSSBAR are the following:
All DREQs, connected to the DMA_CROSSBAR inputs, can be remapped to other lines of the these DMA modules through the CTRL_CORE_DMA_X_DREQ_B_A registers. Each of these registers has a structure described in Table 20-17.
Bits | Field Name | Description | Type | Note |
---|---|---|---|---|
31:24 | RESERVED | R | ||
23:16 | DMA_X_DREQ_A_IRQ_A | Selects a DMA request source signal for the DMA_X_DREQ_A_IRQ_A DMA line | RW | X is summarization. It is equal to:
A is also summarization. It shows the number of the DREQ line for the corresponding DMA module. A is equal to 0, 1, 2, ..., and so on, depending on the count of the DMA lines controlled by the DMA_CROSSBAR module. For more details, see Table 20-18. |
0x0: Reserved | ||||
0x1: Reserved | ||||
0x2: Maps DMA_CROSSBAR input 2 to DMA_X_DREQ_A_IRQ_A DMA line | ||||
0x3: Maps DMA_CROSSBAR input 3 to DMA_X_DREQ_A_IRQ_A DMA line | ||||
0x-: .................................................... | ||||
0x32: Maps DMA_CROSSBAR input 50 to DMA_X_DREQ_A_IRQ_A DMA line | ||||
0x-: .................................................... | ||||
0xCC to 0xFF: Reserved | ||||
15:8 | RESERVED | R | ||
7:0 | DMA_X_DREQ_B_IRQ_B | Selects a DMA request source signal for the DMA_X_DREQ_B_IRQ_B DMA line | RW | B is also summarization. It shows the number of the DREQ line for the corresponding DMA module. B is equal to 0, 1, 2, ..., and so on, depending on the count of the DMA lines controlled by the DMA_CROSSBAR module. For more details, see Table 20-18. |
0x0: Reserved | ||||
0x1: Reserved | ||||
0x2: Maps DMA_CROSSBAR input 2 to DMA_X_DREQ_B_IRQ_B DMA line | ||||
0x3: Maps DMA_CROSSBAR input 3 to DMA_X_DREQ_B_IRQ_B DMA line | ||||
0x-: .................................................... | ||||
0x32: Maps DMA_CROSSBAR input 50 to DMA_X_DREQ_B_IRQ_B DMA line | ||||
0x-: .................................................... | ||||
0xCC to 0xFF: Reserved |
Figure 20-11 represents the way in which the DMA_CROSSBAR module works. It shows the device modules and their DREQs connected to the DMA_CROSSBAR inputs, the structure of the cross-bar and its outputs connected to the device DMA modules.
Each DMA_CROSSBAR control register has two 8-bit fields. Each 8-bit field is associated only with one line of certain DMA module. Through this 8-bit field any of the DREQs connected to the DMA_CROSSBAR inputs can be mapped to the DMA line associated with this 8-bit field. For example, the register CTRL_CORE_DMA_EDMA_DREQ_62_63 is associated with DMA_EDMA_DREQ_62 and DMA_EDMA_DREQ_63 lines. The 8-bit field CTRL_CORE_DMA_EDMA_DREQ_62_63[7:0] DMA_EDMA_DREQ_62_IRQ_62 is associated only with DMA_EDMA_DREQ_62 line of the DMA_EDMA module. Setting this bit field to any other value different than its reset value will map another DREQ from the device modules to the DMA_EDMA_DREQ_62 line. The default (reset) value of this bit field is 0x3F which corresponds to the DMA_CROSSBAR_63 input. The UART5_DREQ_TX is connected to this cross-bar input. Setting another register to 0x3F will cause the UART5_DREQ_TX to be mapped to another DMA line. For example, if the CTRL_CORE_DMA_EDMA_DREQ_30_31[23:16] DMA_EDMA_DREQ_31_IRQ_31 is set to 0x3F the UART5_DREQ_TX will be mapped to the DMA_EDMA_DREQ_31 line. The same logic also applies to the other lines of the device DMAs.
Table 20-18 shows which lines of each DMA are associated with the DMA_CROSSBAR control registers. The rest of the lines (not listed in the table) cannot be controlled by the cross-bar registers.
DMA_SYSTEM DREQ Lines | DMA_EDMA DREQ Lines | DMA_DSP1_EDMA DREQ Lines | DMA_DSP2_EDMA DREQ Lines |
---|---|---|---|
DMA_SYSTEM_DREQ_0 to DMA_SYSTEM_DREQ_126 | DMA_EDMA_DREQ_0 to DMA_EDMA_DREQ_63 | DMA_DSP1_DREQ_0 to DMA_DSP1_DREQ_19 | DMA_DSP2_DREQ_0 to DMA_DSP2_DREQ_19 |
The individual connection between all module DREQs and all DMA_CROSSBAR inputs is shown in Section 18.1.3.2, Mapping of DMA Requests to DMA_CROSSBAR Inputs of Section 18.1, System DMA.
In addition, the CTRL_CORE_OVS_DMARQ_IO_MUX register is used to select for observation on two external pads any DREQ connected to the DMA_CROSSBAR inputs. Using the CTRL_CORE_OVS_DMARQ_IO_MUX[15:8] OVS_DMARQ_IO_MUX_2 bit field all DREQs can be mapped to the obs_dmarq2 signal. The CTRL_CORE_OVS_DMARQ_IO_MUX[7:0] OVS_DMARQ_IO_MUX_1 bit field maps all DREQs to the obs_dmarq1 signal. For example, setting the CTRL_CORE_OVS_DMARQ_IO_MUX[7:0] OVS_DMARQ_IO_MUX_1 to 0x6 maps the DISPC_DREQ to the obs_dmarq1 line and thus this DREQ can be observed.