Modes Of Operation - Samsung S5PC100 User Manual

S5PC100 USER'S MANUAL (REV1.0)

4 MODES OF OPERATION

The application operates the Link either in DMA mode or in Slave mode. The application cannot operate the core
using DMA and Slave modes simultaneously.
4.1 DMA MODE
USB OTG host uses the AHB Master interface to transmit packet data fetch (AHB to USB) and receive data
update (USB to AHB). The AHB master uses the programmed DMA address (HCDMAn register in Host mode and
DIEPDMAn/ DOEPDMAn register in Device mode) to access the data buffers.
4.2 SLAVE MODE
USB OTG can operate either in transaction-level operation or in pipelined transaction-level operation. The
application handles one data packet at a time per channel / endpoint in transaction-level operations. In pipelined
transaction-level operation, the application programs the OTG to perform multiple transactions. The advantage of
pipelined operation is that the application is not interrupted on packet basis.
5 POWER MANAGEMENT UNIT SETTING
A register in Power Management Unit has to be set for USB to work appropriately. (OTHERS = 0xE010_8200)
OTHERS
USB_SIG_MASK
In order to start USB transaction, USB_SIG_MASK is set to 1'b1 and then USB OTG should be initialized. On the
other hand, USB_SIG_MASK is set to 1'b0 to prevent the unwanted signal transfer from OTG PHY to internal
logic in case USB OTG voltage sources of 1.2V and 3.3V are not supplied.
There are two ways to minimize the current consumption when USB OTG is not used. In case USB OTG voltage
sources of 1.2V and 3.3V are provided, USB_SIG_MASK is set to 1'b1 and USB OTG should be initialized and
then entered into standby state. In the other case, USB_SIG_MASK is set to 1'b0.
Bit
The role of this bit is to bypass or block the signals
transferred from USB OTG PHY to internal logic. In order
to start USB transaction, This bit is set to 1 and then
USB_PHY initialization sequence begins.
[16]
Caution: If USB_PHY is not used in your system, this
bit is set to 0.
0 = Mask
1 = Unmask
Description
USB2.0 HS OTG
Reset Value
0
8.10-3