enCoRe™ V CY7C643xx, enCoRe™ V LV CY7C604xx TRM, Document No. 001-32519 Rev *H
34
Supervisory ROM (SROM)
Address F8h is the return code byte for all SROM functions
(except Checksum and TableRead); for this function, the
only acceptable values are 00h, 02h, and 06h. Address FCh
is the fail count variable. After POR, WDR, or XRES, the
variable is initialized to 00h by the SROM. Each time the
Checksum fails, the fail count is incremented. Therefore, if it
takes two passes through SWBootReset to get a good
Checksum, the fail count is 01h.
3.1.2.2
ReadBlock Function
The ReadBlock function is used to read 128 contiguous
bytes from flash: a block. The enCoRe V device has 32 KB
of flash and has two hundred fifty-six 128-byte blocks. Valid
block IDs are 00h to FFh.
The first thing the ReadBlock function does is check the pro-
tection bits to determine if the wanted BLOCKID is readable.
If read protection is turned on, the ReadBlock function exits
setting the accumulator and KEY2 back to 00h. KEY1 has a
value of 01h indicating a read failure.
If read protection is not enabled, the function reads 128
bytes from the flash using a
ROMX
instruction and stores the
results in SRAM using an
MVI
instruction. The 128 bytes are
stored in SRAM, beginning at the address indicated by the
value of the POINTER parameter. When the ReadBlock
completes successfully, the accumulator, KEY1, and KEY2
has a value of 00h.
Note
An
MVI [expr], A
stores the flash block contents in
SRAM meaning that you can use the MVW_PP register to
indicate which SRAM pages receive the data.
3.1.2.3
WriteBlock Function
The WriteBlock function stores data in the flash. No verifica-
tion of the data is performed, but execution time is about
1 ms less than the WriteAndVerify function. The WriteAnd-
Verify function is the recommended method for altering the
data in one flash block (
see “WriteAndVerify Function” on
). Data moves 128 bytes at a time from SRAM to
flash. This is a two-step process, the first step is to load the
page latch with 128 bytes of data and it is followed by the
programming of the corresponding block of flash. No erase
is needed before WriteBlock.
If write protection is turned on, then the WriteBlock function
exits, setting the accumulator and KEY2 back to 00h. KEY1
has a value of 01h, indicating a write failure. Write protection
is set when the enCoRe V device is programmed externally
and cannot be changed through the
SSC
function.
The BLOCKID of the flash block, where the data is stored,
must be determined and stored at SRAM address FAh. Valid
block IDs are 00h to FFh.
Table 3-5. SRAM Map Post SWBootReset (00h)
Address
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
0x0_
0x00
0x00
0x00
??
??
??
??
??
??
??
??
??
??
??
??
??
0x1_
??
??
??
??
??
??
??
??
??
??
??
??
??
??
??
??
0x2_
??
??
??
??
??
??
??
??
??
??
??
??
??
??
??
??
0x3_
??
??
??
??
??
??
??
??
??
??
??
??
??
??
??
??
0x4_
??
??
??
??
??
??
??
??
??
??
??
??
??
??
??
??
0x5_
??
??
??
??
??
??
??
??
??
??
??
??
??
??
??
??
0x6_
??
??
??
??
??
??
??
??
??
??
??
??
??
??
??
??
0x7_
??
??
??
??
??
??
??
??
??
??
??
??
??
??
??
??
0x8_
??
??
??
??
??
??
??
??
??
??
??
??
??
??
??
??
0x9_
??
??
??
??
??
??
??
??
??
??
??
??
??
??
??
??
0xA_
??
??
??
??
??
??
??
??
??
??
??
??
??
??
??
??
0xB_
??
??
??
??
??
??
??
??
??
??
??
??
??
??
??
??
0xC_
??
??
??
??
??
??
??
??
??
??
??
??
??
??
??
??
0xD_
0x00
0x00
0x00
0x00
0x00
0x00
0x00
0x00
0x00
0x00
0x00
0x00
0x00
0x00
0x00
0x00
0xE_
0x00
0x00
0x00
0x00
0x00
0x00
0x00
0x00
0x00
0x00
0x00
0x00
0x00
0x00
0x00
0x00
0xF_
0x00
0x00
0x00
0x00
0x00
0x00
??
??
0x00
0x02
0x06
Xx
0x00
0x00
0xn
xx
0x00
0x00
Table 3-6. Flash Memory Organization
enCoRe V
Device
Amount of
Flash
Amount of
SRAM
Number of
Blocks
per Bank
Number of
Banks
CY7C6xxxx,
32 KB
2K Bytes
256
1
Table 3-7. ReadBlock Parameters (01h)
Name
Address
Type
Description
MVW_PP
0,D5h
Register
MVI
write page pointer register.
KEY1
0,F8h
RAM
3Ah.
KEY2
0,F9h
RAM
Stack Pointer value+3, when
SSC
is
executed.
BLOCKID
0,FAh
RAM
Flash block number.
POINTER
0,FBh
RAM
Addresses in SRAM to store returned
data.
