1.4 Block Summary
EMCU Microcontroller Core
- FTDI’s 8 bit Embedded Microcontroller provides an easy to program , efficient Harvard
architecture CPU with 256 bytes of data memory (SRAM). The op-codes are optimised for USB applications and the
EMCU includes several standard on board peripherals including serial I/O with modem control and baud rate generator,
ISA bus peripheral interface and PS/2 keyboard and mouse interface.
The data sheet for the FTDI EMCU microcontroller core is available on request.
OSC 48MHz
– The FTF8U100AX supports the use of either a 48 MHz oscillator or a crystal. , as preferred based on
cost versus additional tuning circuit logic. Appendix B contains reference schematics using a 48MHz crystal – including
a bandpass filter network and DC blocking capacitor (L1 and C4 with C5 on UH8340 application schematic in
Appendix B) advised for reliable operation at 48MHz. Alternatively a 48MHz oscillator can be connected to XTIN using
a 10 Ohm series resistor and with the option to add a smoothing capacitor to ground.
Data SRAM
- 256 bytes of local variable memory.
FTDI Serial Interface Engine
- the FT8U100AX contains an SIE block which provides the following USB functions -
integral DPLL Data Separator, NRZI Encode/Decode, Bit Stuff/Unstuff, Sync Packet Generation and Detection, EOP
and Bus Reset Detect, Parallel <-> Serial Conversion, CRC checking and generation, PID decode and Validation,
Packet Level Handshaking, Suspend/Resume Detection and Signalling
USB Hub Repeater
- this block provides the data routing functionality for the FT8U100AX. This provides, on a per-port
basis, Connect and Disconnect functions, Full / Low Speed Signal Routing, Power Control and Overcurrent Detect,
Suspend and Resume Control as well as Babble detection, End Of Frame Timer and Lock Generation, Low Speed
“Keep Alive Strobe” Generation and Low Speed Data Conversion and Pre-Packet Decode.
Hub Port Power Control
- this block provides Power Control and Overcurrent Detect functions. The FTDI USB Hub
firmware implements several features aimed at improving USB Hub product performance and error reporting in
situations where third party peripherals cause power glitches and USB current violations.
Endpoint Data Buffer
- 256 byte data buffer with expandable endpoint count, providing support for USB devices within
the IC. This provides endpoint buffer management, transmit and receive counters and address to endpoint decoding.
The operation of this block is discussed further in section 4.4, USB Device/EndPoint Registers and Appendix A, part 2
– where EndPoint Data Buffer organisation for the UltraHub reference design is discussed.
Parallel I/O Ports
- this FT8U100AX provides several General Purpose I/O Ports. These bidirectional ports can be
used to tailor the functionality of Hub products using the F8U100AX - providing firmware control of such features as
LED status indicator operation and providing pins to support the wide range of legacy peripherals supported by the
FT8U100AX.
The FT8U100AX contains hardware to support a range of internal peripherals. The necessary interface signals for
these internal peripherals are routed to specific I/O pins under the control of firmware. The Pinout Configuration
Diagram provides details on which I/Os can be used to support each of these peripherals.
PS/2 Keyboard and Mouse I/F
- provides support for legacy PS/2 keyboard and mouse ports. PS/2 mouse I/F
includes support for 2 button and 3 button as well as Thumb Wheel operation.
Serial Port 1/2/3
- Serial Port 1 provides an asynchronous serial port for USB to RS232 communications, Serial Port 2
provides support for USB to IrDA SIR port infra red communications and Serial Port 3 provides hardware support for
USB to IrDA CIR port infra red communications.
Master/Slave 2-wire serial bus
- this provides hardware support for a generic two wire serial bus suitable for monitor
control applications.
FTIr Remote Control Port
- this provides support hardware for USB to FTIr port for remote control applications.
Future Technology Devices Intl.
FT8U100AX Product Data Rev 0.90
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