Datasheet

REV. A–32–
ADuC834
BYTE 1
(0000H)
EDATA1 SFR
BYTE 1
(0004H)
BYTE 1
(0008H)
BYTE 1
(000CH)
BYTE 1
(0FF8H)
BYTE 1
(0FFCH)
BYTE 2
(0001H)
EDATA2 SFR
BYTE 2
(0005H)
BYTE 2
(0009H)
BYTE 2
(000DH)
BYTE 2
(0FF9H)
BYTE 2
(0FFDH)
BYTE 3
(0002H)
EDATA3 SFR
BYTE 3
(0006H)
BYTE 3
(000AH)
BYTE 3
(000EH)
BYTE 3
(0FFAH)
BYTE 3
(0FFEH)
BYTE 4
(0003H)
EDATA4 SFR
BYTE 4
(0007H)
BYTE 4
(000BH)
BYTE 4
(000FH)
BYTE 4
(0FFBH)
BYTE 4
(0FFFH)
01H
00H
02H
03H
3FEH
3FFH
PAGE ADDRESS
(EADRH/L)
BYTE
ADDRESSES
ARE GIVEN IN
BRACKETS
Using the Flash/EE Data Memory
The 4 Kbytes of Flash/EE data memory is configured as 1024 pages,
each of 4 bytes. As with the other ADuC834 peripherals, the
interface to this memory space is via a group of registers mapped
in the SFR space. A group of four data registers (EDATA1–4)
is used to hold the 4 bytes of data at each page. The page is
addressed via the two registers EADRH and EADRL. Finally,
ECON is an 8-bit control register that may be written with one
of nine Flash/EE memory access commands to trigger various
read, write, erase, and verify functions.
A block diagram of the SFR interface to the Flash/EE data
memory array is shown in Figure 20.
ECON—Flash/EE Memory Control SFR
Programming of either the Flash/EE data memory or the Flash/EE
program memory is done through the Flash/EE Memory Control
SFR (ECON). This SFR allows the user to read, write, erase or
verify the 4 Kbytes of Flash/EE data memory or the 56 Kbytes
of Flash/EE program memory.
Table XIV. ECON—Flash/EE Memory Commands
Command Description Command Description
ECON Value (Normal Mode) (Power-On Default) (ULOAD Mode)
01H Results in 4 bytes in the Flash/EE data memory, Not Implemented. Use the MOVC instruction.
READ addressed by the page address EADRH/L,
being read into EDATA 1 to 4.
02H Results in 4 bytes in EDATA1–4 being written to the Results in bytes 0–255 of internal XRAM being written
WRITE Flash/EE data memory, at the page address given by to the 256 bytes of Flash/EE program memory at the page
EADRH. (0 ≤ EADRH < 0400H) address given by EADRH/L (0 ≤ EADRH/L < E0H)
Note: The 4 bytes in the page being addressed must Note: The 256 bytes in the page being addressed must
be pre-erased. be pre-erased.
03H Reserved Command Reserved Command
04H Verifies if the data in EDATA1–4 is contained in the Not Implemented. Use the MOVC and MOVX instructions
VERIFY page address given by EADRH/L. A subsequent read to verify the WRITE in software.
of the ECON SFR will result in a 0 being read if the
verification is valid, or a nonzero value being read to
indicate an invalid verification.
05H Results in the erase of the 4 bytes page of Flash/EE data Results in the 64-bytes page of Flash/EE program memory,
ERASE PAGE memory addressed by the page address EADRH/L addressed by the byte address EADRH/L being erased.
EADRL can equal any of 64 locations within the page. A new
page starts whenever EADRL is equal to 00H, 40H, 80H, or C0H
06H Results in the erase of entire 4 Kbytes of Flash/EE Results in the erase of the entire 56 Kbytes of ULOAD
ERASE ALL data memory. Flash/EE program memory
81H Results in the byte in the Flash/EE data memory, Not Implemented. Use the MOVC command.
READBYTE addressed by the byte address EADRH/L, being read
into EDATA1. (0 ≤ EADRH/L ≤ 0FFFH).
82H Results in the byte in EDATA1 being written into Results in the byte in EDATA1 being written into
WRITEBYTE Flash/EE data memory, at the byte address EADRH/L. Flash/EE program memory at the byte address
EADRH/L (0 ≤ EADRH/L ≤ DFFFH)
0FH Leaves the ECON instructions to operate on the Enters normal mode directing subsequent ECON
EXULOAD Flash/EE data memory. instructions to operate on the Flash/EE data memory
F0H Enters ULOAD mode, directing subsequent ECON Leaves the ECON Instructions to operate on the Flash/EE
ULOAD instructions to operate on the Flash/EE program memory. program memory.
Figure 20. Flash/EE Data Memory Control and Configuration