Overview Of 8-Bit Serial I/O - Fujitsu F2MC-8L MB89620 Series Hardware Manual

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10.

Overview of 8-bit Serial I/O

The 8-bit serial I/O function is the serial transfer of 8-bit data, synchronized with the
shift clock. Two serial I/O are provided, both with the same functions. The shift clock
can be selected one clock from one external and three internal clocks. The data shift
direction can be selected as either LSB first or MSB first.
n Serial I/O Function
The 8-bit serial I/O function is the serial input and output of 8-bit data, synchronized with the
shift clock.
Two serial I/O channels are provided, both with the same functions (8-bit serial I/O-1 and 8-bit
serial I/O-2).
• The serial I/O converts 8-bit parallel data to serial and outputs the serial data. Similarly, the
serial I/O converts input serial data to parallel and stores the data.
• One shift clock can be selected from one external and three internal clocks.
• The serial I/O can control input and output of the shift clock and can output the internal shift
clock.
• The data shift direction (transfer direction) can be selected as either LSB first or MSB first.
Table 10.1 Shift Clock Cycle and Transfer Speed
Internal shift clock (output)
External shift clock (input)
F : Source oscillation
C
t : Instruction cycle (divide-by-four source oscillation)
inst
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CHAPTER 10 8-BIT SERIAL I/O (SERIAL I/O-1 AND SERIAL I/O-2)
Shift clock Clock cycle Frequency (Hz)
2 t 1/(2 t
inst
8 t 1/(8 t
inst
32 t 1/(32 t
inst
2 t or more 1/(2 t
inst inst
Transfer speed
(F =10 MHz)
C
) 1.25 Mbps
inst
) 312.5 kbps
inst
) 78.1 kbps
inst
) or less DC to 1.25 Mbps
MB89620 series