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SDMA Integration
11.3.2 Hardware Requests
11.3.2.1 SDMA Interrupts
DMA4 has four interrupt lines, numbered Lj with j=0..3. Each logical channel can request an interrupt over
any line. The attachment of a channel interrupt event to one of these four external lines is programmable.
The software determines whether it attaches a channel interrupt to a single IRQ line or to multiple IRQ
lines.
There are two different registers per interrupt line:
•
CH_31_0_Lj field shows the status of the different sources of interrupt. If the
bit i is 1, the channel i is the source of interrupt in line j. In contrast to the
registers, the
registers are updated regardless of the
corresponding bits in the
registers.
•
CH_31_0_Lj_EN field masks/unmasks the channel interrupt. If the
bit i is set to 0, the channel interrupt i of the line j is masked.
Each logical channel can generate a number of different interrupt events when enabled (that is, set to 1) in
the
register. Each status bit is updated in the
register only when the
corresponding enable bit is enabled in the
register.
To determine an interrupt source when an interrupt rises on an interrupt line Lj, you must:
•
Identify the channel (LCHi) generating the interrupt.
Read the
.LCHi (LCH0 to LCH31). If LCHi = 1, channel i is the originator of the
interrupt.
•
Identify the interrupt event.
Read the LCHi
. For example, if the drop event (the
[1] DROP bit) is 1, there
will be a request collision.
The interrupt event status bit in the
register is immediately reset after it is written to 1.
The interrupt status bit in the
register is cleared after it is written to 1.
shows the SDMA interrupts.
Table 11-2. SDMA Interrupts
Source
IRQ to MPU INTC
IRQ to IVA2.2 INTC
Description
SDMA_IRQ_0
M_IRQ_12
EVT89
SDMA interrupt request 0
SDMA_IRQ_1
M_IRQ_13
EVT90
SDMA interrupt request 1
SDMA_IRQ_2
M_IRQ_14
N/A
SDMA interrupt request 2
SDMA_IRQ_3
M_IRQ_15
N/A
SDMA interrupt request 3
11.3.2.2 DMA Requests to the SDMA Controller
All peripherals internal to the device use the transition-sensitive scheme for DMA requests. For more
information on the transition-sensitive scheme, see
, SDMA Request Scheme.
lists the SDMA request mapping.
Table 11-3. SDMA Request Mapping
DMA
Source
Description
Request Line
S_DMA_0
Reserved
Reserved
S_DMA_1
SYS_DMA_REQ0
External DMA request 0 (system expansion)
S_DMA_2
SYS_DMA_REQ1
External DMA request 1 (system expansion)
S_DMA_3
GPMC_DMA
GPMC request from prefetch engine
S_DMA_4
Reserved
Reserved
S_DMA_5
DSS_LINE_DMA
Display subsystem - line trigger DMA request
S_DMA_6
SYS_DMA_REQ2
External DMA request 2 (system expansion)
2343
SWPU177N – December 2009 – Revised November 2010
SDMA
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