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Memory Controller
Figure 48 show s a 32-b it read from an 8-bit p age mod e ROM de vice, c ausing four bu rst reads to be performed. A total of eight AHB wait states are added during this transfer, five AHB arbitration cycles and then one for each of the subsequent reads.
WAIT RD and WA ITPA GE are 0. Table 63 provides the timing parameters. Table 64
describes the transactions for Figure 48.

Figure 48: External memory 32-bit burst read from 8-bit memory timing diagram

T8-T9 Read page mode wait state 1.
T9-T10 Read data 1 returned from the static memory.
Read data 1 is provided to the AHB.
Static memory transfer 2, address, chip select, and control signals
submitted to static memory.
T10-T11 Read page mode wait state 1.
T11-T12 Read data 2 returned from the static memory.
Read data 2 is provided to the AHB.
Static memory transfer 3, address, chip select, and control signals
submitted to static memory.
Timing parameters Value
WAITRD 0
WAITOEN 0
WAITPAGE 0

Table 63: Static memory timing parameters

Cycle Description

Table 62: External memory page mode read

ADDR
DATAIN
A+3
SCTSOUT_n
OEOUT_n
AA+1 A+2
D(A)
D(A+1) D(A+2) D(A+3)
clk_out
T0 T1 T2 T3 T4 T5 T6 T7 T8