System Test and Debugging
Élan™SC520 Microcontroller User’s Manual
24-5
Figure 24-1
System Test Mode Timing During a SDRAM Write Cycle (Page Hit)
24.4.1.4
SDRAM Read Cycle in System Test Mode
Figure 24-2 illustrates the timing of a page miss SDRAM read cycle (with a CAS Latency
of 2) during system test mode. To capture the CF_DRAM, BA1–BA0, MA12–MA0, and
MD31–MD0 signals, the logic analyzer or external in-circuit emulation system can use the
DATASTRB signal to identify the appropriate time to latch the information. This information
must be captured on the rising edge of CLKMEMIN when DATASTRB is sampled active.
The CAS latency timing is configured in the SDRAM Timing Control (DRCTMCTL) register
(MMCR offset 12h). The BA1–BA0 and MA12–MA0 bus can be used to determine the
physical address generated by the requesting master.
Figure 24-2
System Test Mode Timing During an SDRAM Read Cycle (Page Miss)
24.4.1.5
Tracing Transactions on the ROM Interface
Tracing transactions on the ROM interface requires only the CF_ROM_GPCS signal if it is
desired to differentiate code fetches from memory read cycles. Only the Am5
x
86 CPU can
be the initiator of ROM accesses. The address bus is non-multiplexed, and thus can be
read directly from the GPA25
±
GPA0 pins during ROM/Flash cycles. The system
Nop
Wr
Nop
Col
a
CLKMEMIN
BA1–BA0
MD31–MD0
DATASTRB
CF_DRAM
Valid on this clock edge
Command
MA12–MA0
Nop
Rd
Act
Nop
Nop
a
b
c
d
Row
Col
CLKMEMIN
BA1–BA0
Command
MD31–MD0
DATASTRB
CF_DRAM
MA12–MA0
Notes:
CAS latency is 2.
Содержание Elan SC520
Страница 1: ...lan SC520 Microcontroller User s Manual Order 22004A...
Страница 4: ...iv lan SC520 Microcontroller User s Manual...
Страница 28: ...Introduction xxviii lan SC520 Microcontroller User s Manual...
Страница 42: ...Architectural Overview 1 14 lan SC520 Microcontroller User s Manual...
Страница 78: ...System Initialization 3 22 lan SC520 Microcontroller User s Manual...
Страница 108: ...Clock Generation and Control 5 10 lan SC520 Microcontroller User s Manual...
Страница 118: ...Reset Generation 6 10 lan SC520 Microcontroller User s Manual...
Страница 148: ...System Arbitration 8 24 lan SC520 Microcontroller User s Manual...
Страница 214: ...SDRAM Controller 10 36 lan SC520 Microcontroller User s Manual...
Страница 230: ...Write Buffer and Read Buffer 11 16 lan SC520 Microcontroller User s Manual...
Страница 288: ...GP Bus DMA Controller 14 22 lan SC520 Microcontroller User s Manual...
Страница 316: ...Programmable Interval Timer 16 8 lan SC520 Microcontroller User s Manual...
Страница 328: ...Software Timer 18 4 lan SC520 Microcontroller User s Manual...
Страница 346: ...Real Time Clock 20 12 lan SC520 Microcontroller User s Manual...
Страница 360: ...UART Serial Ports 21 14 lan SC520 Microcontroller User s Manual...
Страница 414: ...AMDebug Technology 26 8 lan SC520 Microcontroller User s Manual...