UPD6600A NEC, UPD6600A Datasheet - Page 6

• Manufacturer Part Number: UPD6600A
• Description: 4-BIT SINGLE-CHIP MICROCONTROLLER FOR REMOTE CONTROL TRANSMISSION
• Manufacturer: NEC

6
5.
the control register.
to the data pointer.
6.
7.
operations.
8.
R
R
Table referencing for ROM data can be easily executed by calling the ROM contents by setting the ROM address
On reset or “all clear” is input, it becomes undefined.
The accumulator (A) is a 4-bit register. The accumulator plays a major role in each operation.
On reset or “all clear” is input, it becomes undefined.
The arithmetic logic unit (ALU) is a 4-bit operation circuit, and executes simple operations, such as arithmetic
(1)
(2)
Note
0
0
DATA POINTER (R
ACCUMULATOR (A) ……… 4 BITS
ARITHMETIC LOGIC UNIT (ALU) ……… 4 BITS
FLAGS
specified by the STTS instruction, the status flag (F) is set (to 1).
the MSB for the accumulator, the carry flag (C) is set (to 1).
is executed.
specifies the low-order 8 bits in the ROM address. The high-order 2 bits in the ROM address are specified by
(R
10
Status flag
When the status for each pin is checked by the STTS instruction, if the condition coincides with the condition
On reset or “all clear” is input, it becomes undefined.
Carry flag
When the INC (increment) instruction or the RL (rotate left) instruction is executed, if a carry is generated from
The carry flag (C) is also set (to 1), if the contents for the accumulator are “FH”, when the SCAF instruction
On reset or “all clear” is input, it becomes undefined.
, R
00
) for the data memory can serve as the data pointer for the ROM.
PD6600A: AD
Control registers
(P )
AD
1
9
Note
AD
0
)
8
9
= 0
Figure 6-1. Accumulator Organization
Figure 5-1. Data Pointer Organization
AD
7
A
AD
3
6
R
10
A
2
AD
5
A
AD
1
4
A
0
AD
3
A
AD
2
R
00
AD
1
AD
PD6124A, 6600A
0
R
0