Toshiba H1 Series - Manual (Page 249)

TMP92CZ26A
92CZ26A-246
3.11.4 Description of Registers
NAND Flash Control 0 Register
7 6 5 4 3 2 1 0
bit Symbol WE ALE CLE CE0 CE1 ECCE BUSY ECCRST
Read/Write R/W R/W R/W R/W R/W R/W R W
After reset 0 0 0 0 0 0 0 0
Function
WE
enable
0: Disable
1: Enable
ALE
control
0: “L” out
1: “H” out
CLE
control
0: “L” out
1: “H” out
0 CE
control
0: “H” out
1: “L” out
1 CE
control
0: “H” out
1: “L” out
ECC circuit
control
0: Disable
1: Enable
NAND
Flash
state
1: Busy
0: Ready ECC
reset
control
0:
−
1: Reset
*Always
read as
“0”.
15 14 13 12 11 10 9 8
bit Symbol SPLW1 SPLW0 SPHW1 SPHW0 RSECCL RSEDN RSESTA RSECGW
Read/Write R/W W R/W
After reset 0 0 0 0 0 0 0 0
Function
Strobe pulse width
(Low width of NDRE ,
NDWE )
Inserted width
= (f
SYS
)
× (set value)
Strobe pulse width
(High width of NDRE ,
NDWE )
Inserted width
= (f
SYS
)
× (set value)
Reed-
Solomon
ECC
latch
0: Disable
1: Enable
Reed-
Solomon
operation
0: Encode
(Write)
1: Decode
(Read)
Reed-
Solomon
error
calculation
start
0: −
1: Start
*Always
read as
“0”.
Reed-
Solomon
ECC
generator
write
control
0: Disable
1: Enable
Figure 3.11.5 NAND Flash Mode Control 0 Register
(a) <ECCRST >
The <ECCRST> bit is used for both Hamming and Reed-Solomon codes.
When NDFMCR1<ECCS>=“0”, setting this bit to “1” clears the Hamming ECC in the
ECC generator. When NDFMCR1<ECCS>=“1”, setting this bit to “1” clears the
Reed-Solomon ECC. Note that this bit is ineffective when NDFMCR0<ECCE>=“0”. Before
writing to this bit, ensure that NDFMCR0<ECCE>=“1”.
(b) <BUSY>
The <BUSY> bit is used for both Hamming and Reed-Solomon codes.
This bit is used to check the state of the NAND Flash memory (NDR/B pin). It is set to “1”
when the NAND Flash is “busy” and to “0” when it is “ready”.
Since the NDFC incorporates a noise filter of several states, a change in the NDR/B pin
state is reflected on the <BUSY> flag after some delay. It is therefore necessary to inert a
delay time by software (e.g. ten NOP instructions) before checking this flag.
NDFMCR0
(08C0H)
Read-modify-
write
instructions
cannot be
used.
(08C1H)
Read-modify-
write
instructions
cannot be
used.
Address input
Read
command Delay
time
Sensing <BUSY> flag
NDWE pin
NDCLE pin
NDALE pin
NDR/B pin
<BUSY> flag