Z8 Encore! XP® 4K Series
Product Specification
145
Flash Status Register
The Flash Status (FSTAT) register indicates the current state of the Flash Controller. This
register can be read at any time. The read-only Flash Status Register shares its Register
File address with the Write-only Flash Control Register.
Table 82. Flash Status Register (FSTAT)
BITS
7
6
5
4
3
2
1
0
Reserved
FSTAT
FIELD
RESET
R/W
0
0
0
0
0
0
0
0
R
R
R
R
R
R
R
R
FF8H
ADDR
Reserved—Must be 0.
FSTAT—Flash Controller Status
000000 = Flash Controller locked.
000001 = First unlock command received (73H written).
000010 = Second unlock command received (8CH written).
000011 = Flash Controller unlocked.
000100 = Sector protect register selected.
001xxx = Program operation in progress.
010xxx = Page erase operation in progress.
100xxx = Mass erase operation in progress
Flash Page Select Register
The Flash Page Select (FPS) register shares address space with the Flash Sector Protect
Register. Unless the Flash controller is unlocked and written with 5EH, writes to this
address target the Flash Page Select Register.
The register is used to select one of the 8 available Flash memory pages to be programmed
or erased. Each Flash Page contains 512 bytes of Flash memory. During a Page Erase
operation, all Flash memory having addresses with the most significant 7-bits given by
FPS[6:0] are chosen for program/erase operation.
PS022815-0206
Flash Memory
ZILOG [ ZILOG, INC. ]
