Pointer Incrementation - ST STM32F413 Reference Manual

Advanced arm-based 32-bit mcus

Hide thumbs Also See for STM32F413:

The stream has access to the AHB source or destination port only if the arbitration of the

corresponding stream is won. This arbitration is performed using the priority defined for

each stream using the PL[1:0] bits in the DMA_SxCR register.

When memory-to-memory mode is used, the Circular and direct modes are not allowed.

1. For double-buffer mode.

Pointer incrementation

Peripheral and memory pointers can optionally be automatically post-incremented or kept

constant after each transfer depending on the PINC and MINC bits in the DMA_SxCR

Disabling the Increment mode is useful when the peripheral source or destination data are

accessed through a single register.

If the Increment mode is enabled, the address of the next transfer will be the address of the

previous one incremented by 1 (for bytes), 2 (for half-words) or 4 (for words) depending on

the data width programmed in the PSIZE or MSIZE bits in the DMA_SxCR register.

In order to optimize the packing operation, it is possible to fix the increment offset size for

the peripheral address whatever the size of the data transferred on the AHB peripheral port.

The PINCOS bit in the DMA_SxCR register is used to align the increment offset size with

the data size on the peripheral AHB port, or on a 32-bit address (the address is then

incremented by 4). The PINCOS bit has an impact on the AHB peripheral port only.

If the PINCOS bit is set, the address of the following transfer is the address of the previous

one incremented by 4 (automatically aligned on a 32-bit address), whatever the PSIZE

value. The AHB memory port, however, is not impacted by this operation.

Figure 27. Memory-to-memory mode

DocID029473 Rev 3

Direct memory access controller (DMA)