em78f644nso28s ELAN Microelectronics Corp, em78f644nso28s Datasheet - Page 26

• 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
16 •
6.1.4 R3 (Status Register)
Bits 7 ~ 5: Not used, set to “0” all the time.
Bit 4 (T):
Bit 3 (P): Power down bit
Bit 2 (Z):
Bit 1 (DC): Auxiliary carry flag
Bit 0 (C): Carry flag
6.1.5 R4 (RAM Select Register)
Bits 7 ~ 6: Used to select Bank 0 ~ Bank 3
Bits 5 ~ 0: Used to select registers (Address: 00~3F) in indirect addressing mode.
See the data Memory Configuration in Figure 6-1b above.
6.1.6 Bank 0 R5 (PORT5)
Bit 7 ~ 0 (P57 ~ P50): 8-bit Port5 I/O data register
You can use IOC5 register to define each bit as input or output.
Bit 7
Bit 7
P57
-
For F642/542N, Bit 7 is unused. Set to “0” all the time.
For F641/541N, Bit 7 ~ Bit 6 are unused. Set to “0” all the time.
For F642/542N, Bit 6, Bit 3 ~ Bit 1 are unused. Set to “0” all the time.
For F641/541N, Bit 6, Bit 3 ~ Bit 1 are unused. Set to “0” all the time.
Time-out bit
Set to “1” with the "SLEP" and "WDTC" commands, or during power up
Set to “1” during power-on or by a "WDTC" command and reset to “0” by
Zero flag
Set to "1" if the result of an arithmetic or logic operation is zero.
and reset to “0” by WDT time-out.
a "SLEP" command.
Bit 6
Bit 6
P56
-
Bit 5
Bit 5
P55
-
Bit 4
Bit 4
P54
T
(This specification is subject to change without further notice)
NOTE
NOTE
Bit 3
Bit 3
P53
P
Product Specification (V1.0) 05.05.2010
Bit 2
Bit 2
P52
Z
Bit 1
Bit 1
P51
DC
Bit 0
Bit 0
P50
C