PSD4235F1-12B81 View Datasheet(PDF) - STMicroelectronics
Part Name
Description
Manufacturer
PSD4235F1-12B81 Datasheet PDF : 93 Pages
| |||
PSD4000 Series
6.0
Table 5.
PSD4000
Pin
Descriptions
Preliminary Information
The following table describes the pin names and pin functions of the PSD4000. Pins that
have multiple names and/or functions are defined using PSDsoft.
Pin Name
ADIO0-7
ADIO8-15
CNTL0
CNTL1
CNTL2
Pin*
(TQFP
Pkg.) Type
3-7 I/O
10-12
13-20 I/O
59
I
60
I
40
I
Description
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
AD[0:7] to this port.
2. If your MCU does not have a multiplexed address/data bus,
connect A[0:7] 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
was 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
AD[8:15] to this port.
2. If your MCU does not have a multiplexed address/data bus,
connect A[8:15] 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 was selected. The addresses on this port are passed
to the PLDs.
The following control signals can be connected to this port,
based on your MCU:
1. WR — active-low write input.
2. R_W — active-high read/active low write input.
3. WRL — Write to low byte, active low
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 port,
based on your MCU:
1. RD — active-low read input.
2. E — E clock input.
3. DS — active-low data strobe input.
4. LDS — Strobe for low data byte, active low.
This pin is connected to the PLDs. Therefore, these signals can
be used in decode and other logic equations.
Read or other Control input pin with multiple configurations.
Depending on the MCU interface selected, this pin can be:
1. PSEN — Program Select enable, active low in code fetch
bus cycle (80C51XA mode)
2. BHE — High byte enable.
3. UDS — Strobe for high data byte, 16-bit data bus mode,
active low.
4. SIZ0 — Byte enable input.
5. LSTRB — Low strobe input.
This pin is also connected to PLD as input.
8
Share Link: 