SAM3X8C Atmel Corporation, SAM3X8C Datasheet - Page 438

• Manufacturer Part Number: SAM3X8C
• Manufacturer: Atmel Corporation

26.9.2.3
438
438
SAM3X/A
SAM3X/A
Signal Multiplexing
Figure 26-6. Connection of 2 x 8-bit Devices on a 16-bit Bus: Byte Write Option
Depending on the byte access type (BAT), only the write signals or the byte select signals are
used. To save IOs at the external bus interface, control signals at the SMC interface are multi-
plexed.
access type.
For 16-bit devices, bit A0 of address is unused. When Byte Select Option is selected, NWR1 is
unused. When Byte Write option is selected, NBS0 is unused.
Table 26-5.
Signal Name
Device Type
Byte Access Type (BAT)
NBS0_A0
NWE_NWR0
NBS1_NWR1
A1
Table 26-5
SMC Multiplexed Signal Translation
shows signal multiplexing depending on the data bus width and the byte
SMC
D[15:8]
NCS[3]
A[24:2]
D[7:0]
NWR0
NWR1
NRD
A1
Byte Select
1x16-bit
NBS0
NBS1
NWE
A1
16-bit Bus
Byte Write
2 x 8-bit
NWR0
NWR1
A1
A[23:1]
A[0]
Write Enable
Read Enable
Memory Enable
D[15:8]
A[23:1]
Write Enable
Read Enable
Memory Enable
D[7:0]
A[0]
11057A–ATARM–17-Feb-12
11057A–ATARM–17-Feb-12
8-bit Bus
1 x 8-bit
NWE
A0
A1