C8051F340 Datasheet, PDF (24/282 Pages) List of Unclassifed Manufacturers – Full Speed USB Flash MCU Family

C8051F340/1/2/3/4/5/6/7
1.3. Universal Serial Bus Controller
The Universal Serial Bus Controller (USB0) is a USB 2.0 compliant Full or Low Speed function with inte-
grated transceiver and endpoint FIFO RAM. A total of eight endpoint pipes are available: a bi-directional
control endpoint (Endpoint0) and three pairs of IN/OUT endpoints (Endpoints1-3 IN/OUT).
A 1k Byte block of RAM is used for USB FIFO space. This FIFO space is distributed among Endpoints0-3;
Endpoint1-3 FIFO slots can be configured as IN, OUT, or both IN and OUT (split mode). The maximum
FIFO size is 512 bytes (Endpoint3).
USB0 can be operated as a Full or Low Speed function. On-chip 4x Clock Multiplier and clock recovery cir-
cuitry allow both Full and Low Speed options to be implemented with the on-chip precision oscillator as the
USB clock source. An external oscillator source can also be used with the 4x Clock Multiplier to generate
the USB clock. The CPU clock source is independent of the USB clock.
The USB Transceiver is USB 2.0 compliant, and includes on-chip matching and pull-up resistors. The
pull-up resistors can be enabled/disabled in software, and will appear on the D+ or D- pin according to the
software-selected speed setting (Full or Low Speed).
Transceiver
VDD
D+
D-
Serial Interface Engine (SIE)
Endpoint0
Data
Transfer
Control
IN/OUT
Endpoint1
Endpoint2
IN ^EOnUdpToint3
IN OUT
IN OUT
USB
Control,
Status, and
Interrupt
Registers
CIP-51 Core
USB FIFOs
(1k RAM)
Figure 1.5. USB Controller Block Diagram
24
Rev. 0.5