z16f2811 ZiLOG Semiconductor, z16f2811 Datasheet - Page 37

• Manufacturer Part Number: z16f2811
• Description: High Performance Microcontrollers
• Manufacturer: ZiLOG Semiconductor

Bus Widths
PS022006-0207
000080H
000082H
000080H
Figure 8. Alignment of Word and Quad Operations on 16-bit Memories
The ZNEO CPU accesses 8-bit or 16-bit memories. The data buses of the internal
non-volatile memory and internal RAM are 16-bit wide. The internal peripherals are a mix
of 8-bit and 16-bit peripherals. The external memory bus is configured as an 8-bit or 16-bit
memory bus.
If a Word or Quad operation occurs on a 16-bit wide memory, the number of memory
accesses depends on the alignment of the address. If the address is aligned on an even
boundary, a Word operation takes one memory access and a Quad operation takes two
memory accesses. If the address is on an odd boundary (unaligned), a Word operation
takes two memory accesses and a Quad operation takes three memory accesses.
Figure 8
Aligned Word Access
Aligned Quad Access
illustrates the alignment Word and Quad operations on 16-bit memories.
MSB
MSB
LSB
LSB
000081H
000083H
000081H
P R E L I M I N A R Y
000082H
000080H
000084H
000082H
000080H
Unaligned Word Access
Unaligned Quad Access
LSB
LSB
MSB
MSB
Product Specification
000083H
000081H
000085H
000083H
000081H
ZNEO
™
Address Space
Z16F Series
23