EM78451AP EMC [ELAN Microelectronics Corp], EM78451AP Datasheet - Page 21

• Manufacturer Part Number: EM78451AP
• Description: 8-Bit Microcontroller
• Manufacturer: EMC [ELAN Microelectronics Corp]

Product Specification (V1.2) 05.27.2004
(This specification is subject to change without further notice)
Weakly
Pull-up
PORT
4.5 SERIAL PERIPHERAL INTERFACE MODE
VCC
Rex*
4.5.1
Overview:
Figure 8, 9, and 10 shows how the EM78451 communicates with other devices through
the SPI module. If EM78451 is a master controller, it sends clock through the SCK pin.
A couple of 8-bit data are transmitted and received at the same time. However, if
EM78451 is defined as a slave, its SCK pin could be programmed as an input pin. Data
will continue to be shifted based on both the clock rate and the selected edge.
Features:
Operation in either Master mode or Slave mode,
Three-wire or four-wire synchronous communication; that is, full duplex
Programmable baud rates of communication,
Programming clock polarity, (RD bit7)
Interrupt flag available for the read buffer full,
Up to 8 MHz (maximum) bit frequency,
Fig. 7 (b) The Circuit of I/O Port with R-option (P80, P81)
Overview & Features
ROC
*The Rex is 560K ohm external resistor
1
0
M
U
X
Q
Q
Q
Q
C
L
C
L
R
R
P
P
PCRD
CLK
CLK
D
D
PCWR
PDWR
PDRD
8-Bit Microcontroller
EM78451
IOD
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