PSD4235G2-90U STMicroelectronics, PSD4235G2-90U Datasheet - Page 16

• Manufacturer Part Number: PSD4235G2-90U
• Description: IC FLASH 4MBIT 90NS 80TQFP
• Manufacturer: STMicroelectronics

Specifications of PSD4235G2-90U

• Format - Memory: FLASH
• Memory Type: FLASH
• Memory Size: 4M (512K x 8)
• Speed: 90ns
• Interface: Parallel
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 80-TQFP, 80-VQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-1968

Pin description
2
Table 2.
16/129
ADIO0-
ADIO7
ADIO8-
ADIO15
CNTL0
CNTL1
Pin name
3-7
10-12
13-20 I/O
59
60
Pin description
Pin description (for the LQFP package)
Pin
I/O
I
I
Type
This is the lower Address/Data port. Connect your MCU address or address/data bus
according to the following rules:
1. If your MCU has a multiplexed address/data bus where the data is multiplexed with
the lower address bits, connect AD0-AD7 to this port.
2. If your MCU does not have a multiplexed address/data bus, connect A0-A7 to this
port.
3. If you are using an 80C51XA in burst mode, connect A4/D0 through A11/D7 to this
port.
ALE or AS latches the address. The PSD drives data out only if the READ signal is
active and one of the PSD functional blocks has been selected. The addresses on
this port are passed to the PLDs.
This is the upper Address/Data port. Connect your MCU address or address/data bus
according to the following rules:
1. If your MCU has a multiplexed address/data bus where the data is multiplexed with
the upper address bits, connect A8-A15 to this port.
2. If your MCU does not have a multiplexed address/data bus, connect A8-A15 to this
port.
3. If you are using an 80C51XA in burst mode, connect A12/D8 through A19/D15 to
this port.
ALE or AS latches the address. The PSD drives data out only if the READ signal is
active and one of the PSD functional blocks has been selected. The addresses on
this port are passed to the PLDs.
The following control signals can be connected to this pin, based on your MCU:
1. WR - active low, Write Strobe input.
2. R_W - active high, READ/active low WRITE input.
3. WRL - active low, WRITE to low-byte.
This pin is connected to the PLDs. Therefore, these signals can be used in decode
and other logic equations.
The following control signals can be connected to this pin, based on your MCU:
1. RD - active low, Read Strobe input.
2. E - E clock input.
3. DS - active low, Data Strobe input.
4. LDS - active low, Strobe for low data byte.
This pin is connected to the PLDs. Therefore, these signals can be used in decode
and other logic equations.
Description
PSD4235G2