User`s guide

MSP430 USB Silicon

www.ti.com

2.3 MSP430 USB Module

Features of the MSP430 USB module are as follows:

• Full-speed USB device (12 Mbps). Full-speed is a great match for a 16-bit MCU. It facilitates

communication with a USB host, with simplicity and low system cost. The module does not perform

low- or high-speed transfers; it also does not function as a USB host controller.

• Supports control, interrupt, and bulk transfers. This enables support of the most popular USB

device classes. (Streaming audio using isochronous transfers is not supported.)

• Eight input and eight output endpoints. The more endpoints that are supported, the more USB

interfaces (logical devices) that can be implemented within a composite USB device. MSP430 MCUs

have enough endpoints for as many as seven interfaces in composite (depending on the ones

chosen), which is more than enough for the vast majority of USB applications.

• An integrated 3.3-V LDO, for operation directly from 5-V VBUS from the host. In some

applications, this eliminates the need for an external LDO, because in addition to sourcing the MCU,

the integrated LDO can be used to source the entire system, up to 12 mA. (See the device data sheet

for parameters).

• An integrated D+ pullup. This pullup is the way in which a USB device tells the host it is ready to be

enumerated. In contrast, some USB devices from other vendors require external circuitry to enable the

pullup.

• Programmable PLL. An integrated PLL generates the 48-MHz clock needed for USB operation. The

reference for this PLL comes from the MCU's XT2 oscillator. A wide variety of sources can be used for

the reference.

• Integrated transceiver (PHY). There is no need to buy one separately.

Figure 1 shows a system block diagram.

Figure 1. MSP430 USB Block Diagram

Parts of this block diagram are described as part of the MSP430 USB hardware reference design in

Section 5. The ultimate reference for the module is the USB chapter of the MSP430x5xx and

MSP430x6xx Family User's Guide (SLAU208).

Starting a USB Design Using MSP430™ MCUs SLAA457A–September 2013–Revised May 2014

Submit Documentation Feedback