Motorola C200, Service Manual, Page: 55 / 156

BenQ Rev 1.0
3.1.2 Pulse Width Tones (PWT)
The function of the PWT is to generate a modulated frequency
signal for the external buzzer. Frequency is programmable between
349 Hz and 5276 Hz with 12 half tone frequencies per octave. The
volume is also programmable.
3.1.3 Pulse Width Light (PWL)
This module allows the control of the backlight of LCD and keypad
by employing a 4096 bit random sequence.
3.1.4 MODEM-UART
This UART interface is compatible with the NS 16C750 device which
is devoted to the connection to a MODEM through a standard wired
interface. The module integrates two 64 words (9 and 11 bits)
receive and transmit FIFOs which trigger levels are programmable.
All modem operations are controllable either via a software interface
or using hardware flow control signals. In 56f16, we implement
software flow control by only two signals: TXD0 and RXD0.
3.1.5 I2C master serial interface (I2C)
The I2C (Philips standard) is a half-duplex serial port using 2 lines
(data and clock) for data transmission with software addressable
external devices. In 56f16, we employ I2C bus to control LCD
module.
The I2C signals are defined as follows:
I2C_SCL : programmed to the fast transmission mode (400KHz)
I2C_SDA : the serial bi-directional data of the LCM controller
3.1.6 General Purposes I/O (GPIO)
Ulysse provides 16 GPIOs configurable in read or write mode by
internal registers. In 56f16, we utilize 3 of them as follows:
IO0 : to control vibrator; ‘L’: idle, ‘H’: activate vibrator
IO3 : to control phone jack configuration; ‘L’: data cable, ‘H’:
hands-free
IO13 : to detect accessory plug-in at phone jack; ‘H’: idle, ‘L’: plug-in
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