W681308DG Datasheet, PDF (28/64 Pages) Nuvotem Talema – W681308 USB Audio Controller from Nuvoton integrates fast 8051 Microcontroller Unit (MCU)

W681308
XXXX PRODUCT DESCRIPTION
8.7
Serial Port (UART)
The MCU serial port is a full-duplex port, and the MCU provides additional features, such as Frame Error Detection and
Automatic Address Recognition. The serial port is capable of synchronous and asynchronous communication. In
synchronous mode, the MCU generates the clock and operates in half-duplex mode. In asynchronous mode, the serial port
can simultaneously transmit and receive data. The transmit register and the receive buffer are both addressed as SBUF, but
any write to SBUF writes to the transmit register while any read from SBUF reads from the receive buffer. The serial port can
operate in four modes: MOD 0, MOD 1, MOD 2 and MOD 3.
98H
SCON
Bit 7
SM0/FE
Bit 6
SM1
Bit 5
SM2
Bit 4
REN
Bit 3
TB8
Table 10 Serial Control SCON SFR
Bit 2
RB8
Bit 1
TI
Bit 0
RI
8.8
OTP ROM
The W681308 internal OTP ROM is designed to store all application firmware.
ƒ 8kB One-Time Programmable Logic Device
The OTP programming is done by the injection of hot electrons which are generated by avalanche impact ionization in the bit
cell. User can enter JTAG mode to program 8k OTP ROM through JTAG interface pins and signal of PCMT pin will go high
simultaneously. The signal of pin PCMT can be used to control external hardware device to apply 6.75V or 3.3V to
programming voltage pin VPP. The cells are initialized by ultraviolet light through internal photoemission from the floating
gate.
ƒ Enable OTP Read Protection
You can write zero to bit 7 of OTP address 0x1fff to turn on the read protection feature.
28
Rev1.2