Rainbow Electronics ATmega128L - Manual (Page 292)

292
ATmega128(L)
2467B–09/01
Notes: 1. t
WLRH
is valid for the Write Flash, Write EEPROM, Write Fuse Bits and Write Lock
Bits commands.
2. t
WLRH_CE
is valid for the Chip Erase command.
Serial Downloading Both the Flash and EEPROM memory arrays can be programmed using the serial SPI
bus while RESET is pulled to GND. The serial interface consists of pins SCK, MOSI
(input) and MISO (output). After RESET is set low, the Programming Enable instruction
needs to be executed first before program/erase operations can be executed. NOTE, in
Table 128 on page 292, the pin mapping for SPI programming is listed. Not all parts use
the SPI pins dedicated for the internal SPI interface. Note that throughout the descrip-
tion about Serial downloading, MOSI and MISO are used to describe the serial data in
and serial data out respectively. For ATmega128 these pins are mapped to PDI and
PDO.
Serial Programming Pin
Mapping
t
XLPH
XTAL1 Low to PAGEL high 0 ns
t
PLXH
PAGEL low to XTAL1 high 150 ns
t
BVPH
BS1 Valid before PAGEL High 67 ns
t
PHPL
PAGEL Pulse Width High 150 ns
t
PLBX
BS1 Hold after PAGEL Low 67 ns
t
WLBX
BS2/1 Hold after WR Low 67 ns
t
PLWL
PAGEL Low to WR Low 67 ns
t
BVWL
BS1 Valid to WR Low 67 ns
t
WLWH
WR Pulse Width Low 150 ns
t
WLRL
WR Low to RDY/BSY Low 0 1
µs
t
WLRH
WR Low to RDY/BSY High
(1)
3.7 4.5 ms
t
WLRH_CE
WR Low to RDY/BSY High for Chip Erase
(2)
7.5 9 ms
t
XLOL
XTAL1 Low to OE Low 0 ns
t
BVDV
BS1 Valid to DATA valid 0 250 ns
t
OLDV
OE Low to DATA Valid 250 ns
t
OHDZ
OE High to DATA Tri-stated 250 ns
Table 127. Parallel Programming Characteristics, V
CC
= 5 V ± 10% (Continued)
Symbol Parameter Min Typ Max Units
Table 128. Pin Mapping Serial Programming
Symbol Pins I/O Description
MOSI (PDI) PE0 I Serial data in
MISO (PDO) PE1 O Serial data out
SCK PB1 I Serial clock