Contents
Where can I find the Z80 CPU user manual?
Z80 CPU User’s Manual UM008004-1204 This publication is subject to replacement by a later edition. To determine whether a later edition exists, or to request copies of publications, contact: ZiLOG Worldwide Headquarters 532 Race Street San Jose, CA 95126-3432 Telephone: 408.558.8500 Fax: 408.558.8300 www.ZiLOG.com Document Disclaimer
What does 8 bit mean on a Z80 CPU?
The Z80 is an 8-bit CPU which means that all its data is in 8 bits or a single byte. All of the registers internal to the CPU (registers are temporary storage blocks used for quick maths!), are 8-bits in size while the program counter, which points to where the program is currently running, is 16 bits.
How big is the memory on a Z80?
Because the program counter is 16-bits in size, the external address for the Z80, which selects memory and I/O (inputs/outputs) locations, is also 16-bits in size. This means that the maximum amount of memory that the Z80 can directly access is 2^16 = 64KB. The Z80, unlike many microcontrollers, is Von Neumann as opposed to Harvard architecture.
Why are the pins pulled up on the Z80 processor?
The right side of the schematic is the Z80 processor itself and you will note that some pins are pulled up to 5V, some are pulled down to 0V, and others have output LEDs. Pins that are pulled up are input control signals and it is essential that they are pulled up because the Z80 uses active-low logic.
Is the P / V flag set on the Intel 8080?
In the Condition Bits Affected is declared “P/V is reset if overflow; otherwise, it is reset.” I’ve tried to research somewhere and inside the Intel 8080 manual appears that the P flag is set, but the 8080 manual is not as clear as the z80 manual.
When to use odd parity flag in Z80?
Referring to this reference manual: www.zilog.com/docs/z80/um0080.pdf See the bottom of page 78: This flag is also used with logical operations and rotate instructions to indicate the resulting parity is Even. The number of 1 bits in a byte are counted. If the total is Odd, ODD parity is flagged (P=0).
Is the Z80 CPU a trademark of Zilog?
Z80, Z180, Z380 and Z80382 are trademarks or registered trademarks of Zilog, Inc. All other product or service names are the property of their respective owners. Warning: UM008011-0816 Revision History