HD6417660 RENESAS [Renesas Technology Corp], HD6417660 Datasheet - Page 537

• Manufacturer Part Number: HD6417660
• Description: Renesas 32-Bit RISC Microcomputer
• Manufacturer: RENESAS [Renesas Technology Corp]

Section 18 USB Pin Multiplex Controller (USBPM)
18.1
Feature
The USB pin multiplex controller controls the data path to USB transceiver from USB host
controller or USB function controller. This USB pin multiplex controller also incorporates a clock
select control function that selects the clock signal to be provided to the USB host controller and
USB function controller as either an internally generated clock or externally input clock.
Both the USB host controller and the USB function controller are connected to the USB
transceiver via multiplexer that is controlled by the EXCPG control register (EXCPGCR). The
USB transceiver can be connected to USB host controller or USB function controller.
This LSI generates a 48-MHz clock, which is specified by the USB1.1 specifications, by the on-
chip multiplier circuit using a13-MHz clock input from the RDI_REFCLK_IN pin and provides
the clock to the USB host controller and USB function controller. A 48-MHz clock can also be
externally provided to the USB host controller and USB function controller. The on-chip
multiplier circuit allows the user to receive a stable clock from the RF-IC to be connected to this
LSI directly without connecting 48-MHz TCXO externally. Note, however, that a specific length
of jitter may occur when the on-chip multiplier circuit is used. Before using a clock provided from
the on-chip multiplier circuit, check the connectivity to other USB devices.
Figure 18.1 shows the USB pin multiplexer indicating the connection among the on-chip USB
host controller, USB function controller, on-chip port 1 analog USB transceiver, and clock control
circuit.
Rev. 1.00, 02/04, page 499 of 804