ZPSD303B-90JI STMicroelectronics, ZPSD303B-90JI Datasheet - Page 13

• Manufacturer Part Number: ZPSD303B-90JI
• Description: IC MCU PROG 1MB 5V 90NS 44-PLCC
• Manufacturer: STMicroelectronics

Specifications of ZPSD303B-90JI

• Applications: *
• Interface: *
• Voltage - Supply: *
• Package / Case: 44-PLCC
• Mounting Type: Surface Mount
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-3701

8.0
Operating
Modes (MCU
Configurations)
10
PSD3XX Family
The PSD3XX’s four operating modes enable it to interface directly to most 8- and 16-bit
microcontrollers with multiplexed and non-multiplexed address/data busses. The 16-bit
modes are not available to some devices; see Table 1. The following are the four operating
modes available:
Please read the section below that corresponds to your type of MCU. Then check the
appropriate Figure (3A/3B/3C/3D) to determine your pin connections. Table 3 lists the Port
connections in tabular form.
Multiplexed 8-bit address/data bus (Figure 3A)
This mode is used to interface to microcontrollers with a multiplexed 8-bit data bus. Since
the low-order address and data are multiplexed together, your MCU will output an ALE
or AS signal. The PSD3XX contains a transparent latch to demultiplex the address/data
lines internally. All you have to do is connect the ALE/AS signal and select 8-bit multiplexed
bus mode in PSDsoft. If your MCU outputs more than 16 bits of address, and you
wish to connect them to the PSD, connect A16-A18 to Port C and A19 to A19/CSI, where
applicable.
Multiplexed 16-bit address/data bus (Figure 3B)
This mode is used to interface to microcontrollers with a multiplexed 16-bit data bus. Since
the low address bytes and data are multiplexed together, your MCU will output an ALE
or AS signal. The PSD3XX contains a transparent latch to demultiplex the address/data
lines internally. All you have to do is connect the ALE/AS signal and select 8-bit multiplexed
bus mode in PSDsoft. If your MCU outputs more than 16 bits of address, and you
wish to connect them to the PSD, connect A16-A18 to Port C and A19 to A19/CSI, where
applicable.
Non-multiplexed 8-bit data bus (Figure 3C)
This mode is used to interface to microcontrollers with a non-multiplexed 8-bit data bus.
Connect the MCU’s address bus to AD0/A0-AD15/A15 on the PSD. Connect the data bus
signals of your MCU to Port A of the PSD. If your MCU outputs more than 16 bits of
address, and you wish to connect them to the PSD, connect A16-A18 to Port C and A19 to
A19/CSI, where applicable.
Non-multiplexed 16-bit data bus (Figure 3D)
This mode is used to interface to microcontrollers with a non-multiplexed 16-bit data bus.
Connect the MCU’s address bus to AD0/A0-AD15/A15 on the PSD. Connect the low byte
data bus signals of your MCU to Port A, and the high byte data output of your MCU to Port
B of the PSD. If your MCU outputs more than 16 bits of address, and you wish to connect
them to the PSD, connect A16-A18 to Port C and A19 to A19/CSI, where applicable.
For users with multiplexed MCUs that have data multiplexed on address lines other
than A0-A7 note: You can still use the PSD3XX, but you will have to connect your
data to Port A (and Port B where required), as shown in Figure 3C or 3D. That is, you will
be connecting it as if you were using a non-multiplexed MCU. In this case, you must
connect the ALE/AS signal so that the address will still be properly latched. This option is
not available on the 3X1 versions.
Multiplexed 8-bit address/data bus
Multiplexed 16-bit address/data bus
Non-multiplexed 8-bit data bus
Non-multiplexed 16-bit data bus