W90220F Winbond Electronics Corp America, W90220F Datasheet - Page 50

• Manufacturer Part Number: W90220F
• Description: Pa-risc Embedded Controller
• Manufacturer: Winbond Electronics Corp America

The above information is the exclusive intellectual property of Winbond Electroncs Corp. and shall not be dsiclosed or distributed or reproduced without permission from
Winbond.
50
8-bit data bus in output enable mode which are suit for "standard mode" transfering.
FIFO Status Register (FSR)
Port address : 0xf000037b
Bits 0-4 Valid bytes in device data FIFO (Dfifo)
Bit 5
Bit 6
Bit 7
FIFO Control Register (FCR)
Port address : 0xf000037c
DMAen
0
0
During forward transfering, these bits indicate that how many bytes in 16-byte Dfifo still
not be transfered yet. While during reverse transfering, these bits shows the number of
data bytes which received from parallel port interface and not be read by CPU core.
Dfifo data available
Dfifo space available
Dfifo over/under run
Once this bit is set, it will keep on set state until Dfifo or the PPI is reset.
0 = Dfifo contains data bytes less than one "PWord"
1 = Dfifo contains at least one "PWord" of valid data.
0 = Dfifo contains empty locations less than one "PWord"
1 = Dfifo contains at least one "PWord" of empty locations.
0 = Dfifo is not yet over- or under-run
1 = Dfifo is already over- or under-run
FRST
1
1
Dfifo valid bytes
DRST
2
2
Read only
Read/Write
PWord
3
3
4
4
Power-on Default : ---
Power-on Default : 0x0
MOD
DA
5
5
SA
6
6
RDTH
OV
7
7
W90220F
Version 0.84