w83l950d Winbond Electronics Corp America, w83l950d Datasheet - Page 29

• Manufacturer Part Number: w83l950d
• Description: Peripheral Personal Computer Keyboard Controller
• Manufacturer: Winbond Electronics Corp America

8.6
8.7
8.8
Data Pointer Select
Power Control
Program Status Word
DPS.0 This bit is used to select the DPL, DPH pair or DPL1, DPH1 pair as the active Data
Pointer, DPTR. When set to 1, DPL1, DPH1 will be selected, else DPL, DPH will be selected.
DPS.1-7
GF1-0 These two bits are general-purpose user flags.
PD Setting this bit causes the Winbond Keyboard controller to go into the POWERDOWN mode.
In this mode all the clocks are stopped and program execution is frozen.
IDL Setting this bit causes the Winbond Keyboard controller to go into the IDLE mode. In this
mode the clocks to the CPU is stopped, so program execution is frozen. But the clock to the
serial, timer and interrupt blocks is not stopped, and these blocks continue operating
unhindered. The chip can be wakening to operation mode by active interrupt.
CY Carry flag: Set for an arithmetic operation, which results in a carry being generated from the
ALU. It is also used as the accumulator for the bit operations.
AC Auxiliary carry: Set when the previous operation resulted in a carry (during addition) or
borrow (during subtraction) from the high order nibble.
F0 User flag 0: General-purpose flag that can be set or cleared by the user by software.
RS.1-0 Register bank selects bits:
OV
8th bit as a result of the previous operation or vice-versa.
F1 User Flag 1: General-purpose flag that can be set or cleared by the user by software
P Parity flag: Set/cleared by hardware to indicate odd/even number of 1's in the accumulator.
Bit:
Bit:
Bit:
Mnemonic: DPS
Mnemonic: PCON
Mnemonic: PSW
RS1 RS0 Register bank Address
0
0
1
1
Overflow flag: Set when a carry was generated from the seventh bit but not from the
These bits are reserved but will read 0.
0
1
0
1
CY
7
7
7
-
-
0
1
2
3
AC
6
6
-
-
6
00-07h
08-0Fh
10-17h
18-1Fh
5
5
F0
-
-
5
- 20 -
RS1
4
4
-
-
4
Address: 86h
Address: 87h
Address: D0h
GF1
RS0
3
3
-
3
GF0
2
2
-
OV
2
W83L950D
PD
1
1
-
F1
1
DPS.0
IDL
0
0
0
P