cop8cfe9 National Semiconductor Corporation, cop8cfe9 Datasheet - Page 47

• Manufacturer Part Number: cop8cfe9
• Description: 8-bit Cmos Flash Microcontroller With 8k Memory, Virtual Eeprom, And 10-bit A/d
• Manufacturer: National Semiconductor Corporation

11.0 MICROWIRE/PLUS
clock. The SIO register is shifted on each falling edge of the
SK clock. In the alternate SK phase operation, data is shifted
in on the falling edge of the SK clock and shifted out on the
rising edge of the SK clock. Bit 6 of Port G configuration
register selects the SK edge.
SK Phase
Alternate
Alternate
Normal
Normal
FIGURE 28. MICROWIRE/PLUS SPI Mode Interface Timing, Alternate SK Mode, SK Idle Phase being Low
FIGURE 29. MICROWIRE/PLUS SPI Mode Interface Timing, Normal SK Mode, SK Idle Phase being High
FIGURE 27. MICROWIRE/PLUS SPI Mode Interface Timing, Normal SK Mode, SK Idle Phase being Low
G6 (SKSEL)
Config. Bit
TABLE 30. MICROWIRE/PLUS Shift Clock Polarity and Sample/Shift Phase
0
1
0
1
Port G
(Continued)
G5 Data
Bit
0
0
1
1
SO Clocked Out On:
SK Falling Edge
SK Falling Edge
SK Rising Edge
SK Rising Edge
47
A control flag, SKSEL, allows either the normal SK clock or
the alternate SK clock to be selected. Refer to Table 30 for
the appropriate setting of the SKSEL bit. The SKSEL is
mapped into the G6 configuration bit. The SKSEL flag will
power up in the reset condition, selecting the normal SK
signal provided the SK Idle Polarity remains LOW.
SI Sampled On:
SK Falling Edge
SK Falling Edge
SK Rising Edge
SK Rising Edge
20026436
20026438
20026437
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SK Idle
Phase
High
High
Low
Low