Atmel ARM-Based Evaluation Kit for SAM4S16C, 32-Bit ARM® Cortex® Microcontroller ATSAM4S-WPIR-RD ATSAM4S-WPIR-RD Data Sheet

Product codes
ATSAM4S-WPIR-RD
Page of 1231
459
SAM4S Series [DATASHEET]
Atmel-11100G-ATARM-SAM4S-Datasheet_27-May-14
NRD_HOLD = 4; READ_MODE = 1 (NRD controlled)
NWE_SETUP = 3; WRITE_MODE = 1 (NWE controlled)
TDF_CYCLES = 6; TDF_MODE = 1 (optimization enabled).
Figure 26-19. TDF Optimization: No TDF wait states are inserted if the TDF period is over when the next access begins
26.11.3 TDF Optimization Disabled (TDF_MODE = 0)
When optimization is disabled, tdf wait states are inserted at the end of the read transfer, so that the data float 
period is ended when the second access begins. If the hold period of the read1 controlling signal overlaps the data 
float period, no additional tdf wait states will be inserted.
 and 
 illustrate the cases:
read access followed by a read access on another chip select,
read access followed by a write access on another chip select,
read access followed by a write access on the same chip select,
with no TDF optimization. 
NCS0
MCK
NRD
NWE
D[7:0]
Read to Write 
Wait State
TDF_CYCLES = 6
read access on NCS0 (NRD controlled) 
NRD_HOLD= 4
NWE_SETUP= 3
write access on NCS0 (NWE controlled)