PSD4235G2-90U STMicroelectronics, PSD4235G2-90U Datasheet - Page 54

• 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

Page register
14
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Page register
The 8-bit Page register increases the addressing capability of the MCU by a factor of up to
256. The contents of the register can also be read by the MCU. The outputs of the Page
register (PGR0-PGR7) are inputs to the DPLD decoder and can be included in the Sector
Select (FS0-FS7, CSBOOT0-CSBOOT3), and SRAM Select (RS0) equations.
If memory paging is not needed, or if not all eight page register bits are needed for memory
paging, these bits may be used in the CPLD for general logic. See Application Note
AN1154.
Table 6.14
connected to the internal data bus (D0-D7). The MCU can write to or read from the Page
register. The Page register can be accessed at address location CSIOP + E0h.
Figure 10. Page register
and
Figure 10
RESET
R/ W
D 0 - D 7
show the Page register. The eight flip-flops in the register are
D 0
D 1
D 2
D 3
D 4
D 5
D 6
D 7
REGISTER
PAGE
Q 0
Q 1
Q 2
Q 3
Q 4
Q 5
Q 6
Q 7
PGR0
PGR1
PGR2
PGR3
PGR4
PGR5
PGR6
PGR7
DPLD
CPLD
AND
PLD
INTERNAL
SELECTS
AND LOGIC
PSD4235G2
AI02871B