psd813f3 STMicroelectronics, psd813f3 Datasheet - Page 45

• Manufacturer Part Number: psd813f3
• Description: Flash In-system Programmable Isp Peripherals For 8-bit Mcus
• Manufacturer: STMicroelectronics

PSD Interface to a Non-Multiplexed 8-Bit Bus
Figure
MCU with an 8-bit non-multiplexed bus and a
PSD. The address bus is connected to the ADIO
Port, and the data bus is connected to Port A. Port
A is in tri-state mode when the PSD is not access-
ed by the MCU. Should the system address bus
exceed sixteen bits, Ports B, C, or D may be used
for additional address inputs.
Data Byte Enable Reference
MCUs have different data byte orientations. Table
17
ations in different bus WRITE configurations.
Even-byte refers to locations with address A0
equal to '0' and odd byte as locations with A0 equal
to ’1.’
Figure 20. An Example of a Typical 8-bit Non-Multiplexed Bus Interface
shows how the PSD interprets byte/word oper-
20
MCU
RESET
shows an example of a system using a
BHE
ALE
WR
RD
A [ 15:0 ]
D [ 7:0 ]
PSD813F2, PSD833F2, PSD834F2, PSD853F2, PSD854F2
PSD
WR ( CNTRL0 )
RD ( CNTRL1 )
BHE ( CNTRL2 )
RST
ALE ( PD0 )
PORT D
PORT
ADIO
MCU Bus Interface Examples
Figure
connections between the PSD and some popular
MCUs. The PSD Control input pins are labeled as
to the MCU function for which they are configured.
The MCU bus interface is specified using the PS-
Dsoft Express Configuration.
Table 17. Eight-Bit Data Bus
BHE
21
X
X
through
PORT
PORT
PORT
A
B
C
25
show examples of the basic
A0
0
1
D [ 7:0 ]
(OPTIONAL)
A [ 23:16 ]
Even Byte
Odd Byte
D7-D0
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