45181 Parallax Inc, 45181 Datasheet - Page 155

• Manufacturer Part Number: 45181
• Description: SX TECH TOOL KIT NO POWER
• Manufacturer: Parallax Inc
• Series: SXr
• Type: Microcontrollerr

Specifications of 45181

• Contents: SX Book, SX Key, SX Tech Board, Samples, Resonators, Cable and Manual
• Product: Microcontroller Basic Stamps
• Operating Supply Voltage: 5 V
• For Use With/related Products: SX MCUs
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Bit 1:
Bit 0:
The Carry flag also serves as the ninth bit in RL and RR instructions. We can examine the operation of
each of these instructions to further clarify the behavior of the carry flag. Consider the RR instruction
first. When an RR instruction is performed on a RAM byte, the data in the RAM byte is rotated through
the carry flag.
Similarly, when an RL instruction is performed on a RAM byte, the data in the RAM byte is rotated
through the carry flag.
15.2.9 The FSR – File Select Register ($04)
The SX chip utilizes 12-bit op-codes. Instructions that specify a register as an operand can only express
5-bits of the register address. This means that only registers from $00 up to $1F can be accessed. The File
Select Register (FSR) along with the 5-bit register operand is used to provide the ability to access
registers beyond $1F. Figure 25 – Global Register Addressing SX20/28/48/52 (direct) shows how the
FSR’s upper three bits select one of eight RAM banks on the SX20/28. Figure 26 – SX20/28 General
Purpose Register Addressing (direct) shows how the FSR’s upper four bits select one of sixteen RAM
banks on the SX48/52.
Digit Carry (DC)
After an addition:
After a subtraction:
Carry (C)
After an addition:
After a subtraction:
Set (1)
Clear (0) = no carry from bit 4 has occurred
Set (1)
Clear (0) = a borrow from bit 4 has occurred
Set (1)
Clear (0) = no carry has occurred
Set (1)
Clear (0) = a borrow has occurred
= a carry from bit 4 has occurred
= no borrow from bit 4 has occurred
= a carry has occurred
= no borrow has occurred
C
C
Figure 23 - Rotate Right
Figure 24 - Rotate Left
7
7
6
6
SX-Key/Blitz Development System Manual 2.0 Parallax, Inc. Page 155
5
5
4
4
15 Appendix E: SX Data Sheet
3
3
2
2
1
1
0
0