LG KF690 Service Manual page 32

3.6.13 Mode Select and JTAG Interfaces
The mode pins to the ESM6270 device determine the overall operating mode of the ASIC. The options
under the control of the mode inputs are Native mode, which is the normal subscriber unit operation,
ETM mode, which enables the built-in trace mode, and test mode for factory testing. The ESM6270
device meets the intent of the ANSI/IEEE 1149.1A-1993 feature list. The JTAG interface can be used
to test digital interconnects between devices within the mobile station during manufacture.
3.6.14 General-Purpose Input/Output Interface
The ESM6270 device has general-purpose bidirectional input/output pins. Some of the GPIO pins
have alternate functions supported on them. The alternate functions include USB interface, additional
RAM, ROM, general-purpose chip selects, parallel LCD interface, and a UART interface. The function
of these pins is documented in the various software releases.
3.6.15 UART
The ESM6270 device employs three UARTs. UART1 has dedicated pins while UART2 and UART3
share multiplexed pins.
■ UART1 for data
■ UART2 (can be used for SIM interface)
■ UART3 for data
3.6.16 USB
The ESM6270 device integrates a universal serial bus (USB) controller that supports both
unidirectional and bidirectional transceiver interfaces. The USB controller acts as a USB peripheral
communicating with the USB host.
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
3. TECHNICAL BRIEF
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