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Zilog Z80180 User Manual

Page 28

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Z8018x

Family MPU User Manual

UM005003-0703

13

Programmable Reload Timers (PRT, 2 channels)

Clock Serial I/O (CSIO) channel.

Other Z8X180 family members (such as Z80183, Z80S183, Z80185/195)
feature, in addition to these blocks, additional peripherals and are covered
in their associated Product Specification

Clock Generator

This logic generates the system clock from either an external crystal or
clock input. The external clock is divided by two and provided to both
internal and external devices.

Bus State Controller

This logic performs all of the status and bus control activity associated
with both the CPU and some on-chip peripherals. This includes Wait State
timing, RESET cycles, DRAM refresh, and DMA bus exchanges.

Interrupt Controller

This block monitors and prioritizes the variety of internal and external
interrupts and traps to provide the correct responses from the CPU. To
remain compatible with the Z80 CPU, three different interrupt modes are
supported.

Memory Management Unit

The MMU allows the user to map the memory used by the CPU (logically
only 64K) into the 1MB addressing range supported by the Z8X180. The
organization of the MMU object code features compatibility with the Z80
CPU while offering access to an extended memory space. This capability
is accomplished by using an effective common area - banked area
scheme.

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