em78f644nso28s ELAN Microelectronics Corp, em78f644nso28s Datasheet - Page 110

• Manufacturer Part Number: em78f644nso28s
• Description: Flash Series 8-bit Microcontroller
• Manufacturer: ELAN Microelectronics Corp

EM78F648/644/642/641/548/544/542/541N
8-Bit Microcontroller
100 •
6.7 SPI Function
6.7.1 Overview & Features
6.7.1.1 Overview
Figures 6-15a, 6-15b, and 6-16a below, illustrate how the EM78F648N/F548N MCUs
communicate with other devices through SPI module. If the MCUs are a Master
controller, they send clock through the SCK pin. A couple of 8-bit data are transmitted
and received at the same time. However, if the MCUs are defined as a Slave, their
SCK pins could be programmed as an input pin. Data will continue to be shifted
based on both the clock rate and the selected edge. You can also set the SPIS bit
7(DORD) to decide the SPI transmission order, set the SPIS Bit 6 (TD1), Bit 5 (TD0)
to decide the SDO status output delay time (see Section 6.3.30), and set SPICR Bit 3
(SDOC) to decide SDO pin status after serial data output (see Section 6.3.29).
6.7.1.2 Features
Receiving Counter Timing:
Operation in either Master mode or Slave mode
Three-wire or four-wire full duplex synchronous communication
Programmable baud rates of communication,
Programming clock polarity
Interrupt flag available for the read buffer full
SPI transmission order
After serial data output SDO status select
SDO status output delay time
SPI handshake pin
Up to 8 MHz (maximum) bit frequency
Figure 6-14b UART Receiving Counter Timing Diagram
(This specification is subject to change without further notice)
Product Specification (V1.0) 05.05.2010