mg84fl54b Megawin Technology, mg84fl54b Datasheet - Page 51

• Manufacturer Part Number: mg84fl54b
• Description: Full-speed Usb Micro-controller
• Manufacturer: Megawin Technology

17. 2-wire Serial Interface (TWSI)
Features
• Simple yet powerful and flexible communication interface, only two bus lines needed.
• Both Master and Slave operation supported, and device can operate as Transmitter or Receiver.
• 7-bit address space allows up to 128 different Slave addresses.
• Multi-master arbitration support.
• Up to 400 kHz data transfer speed.
• Programmable Slave address with General Call support.
Description
The 2-wire Serial Interface (TWSI) is ideally suited for typical microcontroller applications. The TWSI protocol
allows the systems designer to interconnect up to 128 different devices using only two bi-directional bus lines,
one for clock (SCL) and one for data (SDA). The only external hardware needed to implement this bus is a
single pull-up resistor for each of the TWSI bus lines. All devices connected to the bus have individual
addresses, and mechanisms for resolving bus contention are inherent in the TWSI protocol.
The CPU interfaces to the TWSI through the following four special function registers: SIADR (serial interface
address register), SIDAT (serial interface data register), SICON (serial interface control register) and SISTA
(serial interface status register). And, the TWSI hardware interfaces to the serial bus via two lines: SDA (serial
data line, P2.1) and SCL (serial clock line, P2.0).
TWSI Bus Interconnection
MEGAWIN
SDA
SCL
Device 1
Device 2
MG84FL54B Data sheet
Device 3
.....
Device n
R
VCC
R
Pull-up
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