STR91XF Datasheet, PDF (24/72 Pages) STMicroelectronics – ARM966E-S 16/32-Bit Flash MCU with Ethernet, USB, CAN, AC Motor Control, 4 Timers, ADC, RTC, DMA

Functional overview
STR91xF
the host computer must have a static image of the code being executed for decompressing the
ETM9 data. Because of this, self-modified code cannot be traced.
2.17 Ethernet MAC interface with DMA
STR91xF devices in the 128-pin package provide an IEEE-802.3-2002 compliant Media
Access Controller (MAC) for Ethernet LAN communications through an industry standard
Medium Independent Interface (MII). The STR91xF requires an external Ethernet physical
interface device (PHY) to connect to the physical LAN bus (twisted-pair, fiber, etc.). The PHY is
connected to the STR91xF MII port using as many as 18 signals (see pins which have signal
names MII_* in Table 2).
The MAC corresponds to the OSI Data Link layer and the PHY corresponds to the OSI Physical
layer. The STR91xF MAC is responsible for:
● Data encapsulation, including frame assembly before transmission, and frame parsing/
error detection during and after reception.
● Media access control, including initiation of frame transmission and recover from
transmission failure.
The STR91xF MAC includes the following features:
● Supports 10 and 100 Mbps rates
● Tagged MAC frame support (VLAN support)
● Half duplex (CSMA/CD) and full duplex operation
● MAC control sublayer (control frames) support
● 32-bit CRC generation and removal
● Several address filtering modes for physical and multicast address (multicast and group
addresses)
● 32-bit status code for each transmitted or received frame
● Internal FIFOs to buffer transmit and receive frames. Transmit FIFO depth is 4 words (32
bits each), and the receive FIFO is 16 words deep.
A 32-bit burst DMA channel residing on the AHB is dedicated to the Ethernet MAC for high-
speed data transfers, side-stepping the CPU for minimal CPU impact during transfers. This
DMA channel includes the following features:
● Direct SRAM to MAC transfers of transmit frames with the related status, by descriptor
chain
● Direct MAC to SRAM transfers of receive frames with the related status, by descriptor
chain
● Open and Closed descriptor chain management
2.18 USB 2.0 slave device interface with DMA
The STR91xF provides a USB slave controller that implements both the OSI Physical and Data
Link layers for direct bus connection by an external USB host on pins USBDP and USBPN. The
USB interface detects token packets, handles data transmission and reception, and processes
handshake packets as required by the USB 2.0 standard.
The USB slave interface includes the following features:
24/72