CY8C34_1105 CYPRESS [Cypress Semiconductor], CY8C34_1105 Datasheet - Page 23

• Manufacturer Part Number: CY8C34_1105
• Description: Programmable System-on-Chip (PSoC) DC to 50 MHz operation
• Manufacturer: CYPRESS [Cypress Semiconductor]

5.6 External Memory Interface
CY8C34 provides an External Memory Interface (EMIF) for
connecting to external memory devices. The connection allows
read and write accesses to external memories. The EMIF
operates in conjunction with UDBs, I/O ports, and other
hardware to generate external memory address and control
signals. At 33 MHz, each memory access cycle takes four bus
clock cycles.
5.7 Memory Map
The CY8C34 8051 memory map is very similar to the MCS-51
memory map.
5.7.1 Code Space
The CY8C34 8051 code space is 64 KB. Only main flash exists
in this space. See the
page 21.
Document Number: 001-53304 Rev. *L
PHUB
“Flash Program Memory”
Data,
Data,
and Control
Data,
Address,
Signals
Address,
Signals
Address,
Signals
and Control
and Control
IO IF
Signals
EM Control
section on
Figure 5-1. EMIF Block Diagram
EMIF
UDB
Data Signals
Address Signals
Control Signals
Signals
Other
Control
Figure 5-1
synchronous and asynchronous memories. The CY8C34
supports only one type of external memory device at a time.
External memory can be accessed via the 8051 xdata space; up
to 24 address bits can be used. See
page 25. The memory can be 8 or 16 bits wide.
5.7.2 Internal Data Space
The CY8C34 8051 internal data space is 384 bytes, compressed
within a 256-byte space. This space consists of 256 bytes of
RAM (in addition to the SRAM mentioned in
21) and a 128-byte space for Special Function Registers (SFRs).
See
registers R0-R7. The next 16 bytes are bit-addressable.
DSI to Port
DSI Dynamic Output
Control
Figure
PORTs
PORTs
PORTs
IO
IO
IO
is the EMIF block diagram. The EMIF supports
5-2. The lowest 32 bytes are used for 4 banks of
External _ MEM_ ADDR[23:0]
External _ MEM_ DATA[15:0]
PSoC
Control
®
3: CY8C34 Family
“xdata Space”
Static RAM
Data Sheet
Page 23 of 127
section on
on page