Electrical Specifications
128
November 2002 − Revised January 2005SPRS205D
HR/W
Read Data
n
HRDY
HDS
HAS
HCS
HD[15:0]
(read)
PIA contents
n + 1
n + 2
E11 E12
E15 E16
E20
E13
E1
E2
E19
E14
E6
E8E7
Read Data
E1
E2
E6
E8E7
HCNTL[1:0]
Valid (01) Valid (01)
HBE[1:0]
Valid Valid
NOTES: A. During autoincrement mode, although the EHPI internally increments the memory address, reads of the HPIA register by the hos
will always indicate the base address.
B. In autoincrement mode, if HBE[1:0] are used to access the data as 8-bit-wide units, the HPIA increments only following each high
byte (HBE1 low) access.
C. The falling edge of HCS must occur concurrent with or before the falling edge of HDS. The rising edge of HCS must occu
concurrent with or after the rising edge of HDS. If HDS1 and/or HDS2 are tied permanently active and HCS is used as a strobe
the timing requirements shown for HDS apply to HCS. HRDY is always driven to the same value as its internal state.
Figure 5−34. EHPI Multiplexed Memory (HPID) Read Timings With Autoincrement
