CY8C20X34_08 Datasheet, PDF (41/216 Pages) Cypress Semiconductor – Technical Reference Manual (TRM)

Supervisory ROM (SROM)
4.1.2.7 TableRead Function
The TableRead function gives the user access to part-spe-
cific data stored in the Flash during manufacturing. The
Flash for these tables is separate from the program Flash
and is not directly accessible.
One of the uses of the TableRead function is to retrieve the
values needed to optimize Flash programming for tempera-
ture. More information about how to use these values is in
the section titled “Clocking Strategy” on page 42.
4.1.2.8 EraseAll Function
The EraseAll function performs a series of steps that
destroys the user data in the Flash banks and resets the
protection block in each Flash bank to all zeros (the unpro-
tected state). This function is only executed by an external
programmer. If EraseAll is executed from code, the M8C will
HALT without touching the Flash or protections. See
Table 4-11.
Table 4-11. Flash Tables with Assigned Values in Flash Bank 0
Table 0
Table 1
Table 2
Table 3
F8h
Silicon ID
Voltage
Reference Trim
for 3.3V
reg[1,EA]
Voltage
Reference Trim
for 2.7V
reg[1,EA]
M (cold)
F9h
IMO Trim
for 3.3V
reg[1,E8]
IMO Trim
12 MHz
Vdd = 2.7V
B (cold)
FAh
FBh
Room
Temperature
Calibration
for 3.3V
Room
Temperature
Calibration
for 2.7V
Mult (cold)
Hot
Temperature
Calibration
for 3.3V
Hot
Temperature
Calibration
for 2.7V
M (hot)
FCh
FDh
FEh
FFh
Voltage
Reference Trim
for 5V
reg[1,EA]
IMO Slow Trim
6 MHz
Vdd = 3.3V
IMO Trim
for 5V
reg[1,E8]
IMO Slow Trim
6 MHz
Vdd = 2.7V
Room
Temperature
Calibration
for 5V
IMO Slow Trim
6 MHz
Vdd = 5.0V
Hot
Temperature
Calibration
for 5V
B (hot)
Mult (hot)
00h
01h
4.1.2.9 Checksum Function
The Checksum function calculates a 16-bit checksum over a
user specifiable number of blocks, within a single Flash
bank starting at block zero. The BLOCKID parameter is
used to pass in the number of blocks to checksum. A
BLOCKID value of ‘1’ calculates the checksum of only block
0, while a BLOCKID value of ‘0’ calculates the checksum of
the entire Flash bank.
The 16-bit checksum is returned in KEY1 and KEY2. The
parameter KEY1 holds the lower 8 bits of the checksum and
the parameter KEY2 holds the upper 8 bits of the checksum.
Table 4-12. Checksum Parameters (07h)
Name
KEY1
KEY2
Address
0,F8h
0,F9h
BLOCKID 0,FAh
Type
RAM
RAM
RAM
Description
3Ah
Stack Pointer value+3, when SSC is
executed.
Number of Flash blocks to calculate
checksum on.
4.1.2.10 Calibrate0 Function
The Calibrate0 function transfers the calibration values
stored in a special area of the Flash to their appropriate reg-
isters. This function may be executed at any time to set all
calibration values back to their 5V values. However, it is
unnecessary to call this function. This function is simply doc-
umented for completeness. 3.3V calibration values are
accessed by way of the TableRead function, which is
described in the section titled “TableRead Function” on
page 41.
Table 4-13. Calibrate0 Parameters (08h)
Name
KEY1
KEY2
Address
0,F8h
0,F9h
Type
RAM
RAM
Description
3Ah
Stack Pointer value+3, when SSC is
executed.
Spec. # 001-13033 Rev. *A, February 19, 2008
41
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