TC1775 Datasheet, PDF (50/101 Pages) Infineon Technologies AG – 32-Bit Single-Chip Microcontroller

TC1775
Preliminary
External Bus Unit
The External Bus Unit (EBU) of the TC1775 is the interface between external memories
and peripheral units and the internal memories and peripheral units. The basic structure
of the EBU is shown in Figure 12.
T riC o re
CPU
PMU
with on-chip
Program Memory
Burst Mode
Instruction
Fetches
FPI Bus
Port 4
Port 3
EBU Port 2
DMU
with on-chip
Data M emory
To Peripheral
Units and PCP
Port 1
Port 0
C o n tro l
Lines
A[25:16] and
Chip Select
A[15:0]
A D [3 1 :1 6 ]
A D [1 5 :0 ]
MCA04753
Figure 12 EBU Structure and Interfaces
The EBU is primarily used for the following two operations:
• Communication with external memories or peripheral units via the FPI Bus
• Instruction fetches from the PMU to external Burst Flash program memories
The EBU controls all transactions required for these two operations and in particular
handles the arbitration between these two tasks.
The types of external devices/bus modes controlled by the EBU are:
• INTEL style peripherals (separate RD and WR signals)
• ROMs, EPROMs
• Static RAMs
• Demultiplexed A/D bus
• Multiplexed A/D bus
The PMU controls accesses to external code memories. It especially supports:
– Burst Mode Flash Memories (ROM)
Note: Instruction fetches of the PMU from external Burst Flash program memories are
only possible with 32-bit data bus width.
Data Sheet
46
V1.2, 2002-05