PSD4235G2-90U STMicroelectronics, PSD4235G2-90U Datasheet - Page 35

• 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

PSD4235G2
7
7.1
Detailed operation
As shown in
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The functions of each block are described in the following sections. Many of the blocks
perform multiple functions, and are user configurable.
Memory blocks
The PSD has the following memory blocks:
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The Memory Select signals for these blocks originate from the Decode PLD (DPLD) and are
user-defined in PSDsoft Express.
Table 28
Table 28.
number
Sector
Total
0
1
2
3
4
5
6
7
Memory blocks
PLD blocks
MCU bus Interface
I/O ports
Power management unit (PMU)
JTAG-ISP interface
Primary Flash memory
Secondary Flash memory
SRAM
summarizes the sizes and organisations of the memory blocks.
Sector size
512 Kbytes
Primary Flash Memory
Figure
Memory block size and organization
Kbytes)
(x16,
32
32
32
32
32
32
32
32
3, the PSD consists of six major types of functional blocks:
8 sectors
Sector
Select
signal
FS0
FS1
FS2
FS3
FS4
FS5
FS6
FS7
Secondary Flash Memory
Sector size
32 Kbytes
Kbytes)
(x16,
4
4
4
4
CSBOOT0
CSBOOT1
CSBOOT2
CSBOOT3
4 sectors
Sector
Select
signal
SRAM size
8 Kbytes
Kbytes)
(x16,
4
Detailed operation
SRAM
SRAM
Select
signal
RS0
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