Datasheet

Even-memory byte accesses (CE1# asserted, CE2# de-asserted, A0 = 0), at offsets between 400h
and 4FFh are equivalent to offset 008h accesses. Odd-memory word accesses (CE1# asserted,
CE2# de-asserted, A0 = 1), at these offsets are equivalent to offset 009h accesses. Even-memory
word accesses (CE1# and CE2# asserted, A0 = don’t care), at these offsets are equivalent to offset
000h or 008h word accesses.
Offsets 400h-7FFh do not correspond to actual card data-buffer addresses. Each access within this
offset-range presents a new data byte or word from the data buffer’s FIFO. This data-register
aliasing allows host CPUs to perform memory string-move operations. In a read-from-drive
example, the host can set a source pointer that corresponds to drive-offset 400h and a destination
pointer that corresponds to internal RAM memory. A move-string instruction then transfers data
from the source (flash drive) to RAM as it automatically increments source and destination
pointers. Although the source pointer increments from 400h to 7FFh offsets, the drive internally
accesses only the data register.
PCMCIA’s PC Card standard describes other task file register accesses in the common memory
plane. Truth table 9 shows the PCMCIA-ATA independent memory address mode.
Table 9. PCMCIA-ATA MODE Independent Memory address = 000-00F, 400-7FF
2
Function
ADDR R/W REG# CE2# CE1# OE# WE# IORD# IOWR#
D15-8 D7-0
No Operation
X
1
X H H X X X X High-Z High-Z
Data 000 Read H L L L H H H
Data High Data Low
(see note 3) H H L L H H H Invalid Data
Write H L L H L H H
Data High Data Low
H H L H L H H Invalid Data
Error 001 Read H H L L H H H Invalid Error
H L H L H H H Error Invalid
Set Feature Write H H L H L H H Invalid Feature
H L H H L H H Feature Invalid
Sector Count 002 Read H X L L H H H Invalid
Sect. Cnt.
Write H X L H L H H Invalid
Sect. Cnt.
Sector Number 003 Read H H L L H H H Invalid Sect. No.
H L H L H H H Sect. No. Invalid
Write H H L H L H H Invalid Sect. No.
H L H H L H H Sect. No. Invalid
Cylinder Low 004 Read H X L L H H H Invalid Cyl. Low
Write H X L H L H H Invalid Cyl. Low
Cylinder High 005 Read H H L L H H H Invalid
Cyl. High
H L H L H H H Cyl. High Invalid
Write H H L H L H H Invalid
Cyl. High
H L H H L H H Cyl. High Invalid