GP Bus DMA Controller
14-16
Élan™SC520 Microcontroller User’s Manual
The automatic initialization control mode cannot be used in conjunction with buffer chaining
mode.
14.5.5
Bus Cycles
Table 14-8 shows the four GP-DMA cycle types and the command strobes generated in
each cycle. The GP bus command strobes GPMEMRD and GPMEMWR are asserted for
memory-mapped I/O devices on this bus. The internal memory commands are not shown
in this table.
14.5.5.1
GP Bus I/O to SDRAM
Figure 14-6 shows a GP-DMA read cycle in demand transfer mode.
Figure 14-6
GP-DMA Read in Demand Transfer Mode
Table 14-8
GP-DMA Cycle Types
GP-DMA Initiator GP-DMA Target
Data Transfer Direction
(GP-DMA Cycle Type)
GP Bus Command
Strobes Generated
I/O device
SDRAM
I/O to memory (GP-DMA write)
GPIORD
I/O device
SDRAM
Memory to I/O (GP-DMA read)
GPIOWR
Memory-mapped
I/O device
SDRAM
Memory-Mapped I/O to memory
(GP-DMA write)
GPMEMRD
Memory-mapped
I/O device
SDRAM
Memory to memory-mapped I/O
(GP-DMA read)
GPMEMWR
GPDACKx
daddr[27:0]
GPAEN
GPIOWR, GPMEMWR
GPD15–GPD0
GPTC
dmemr
GPDRQx
Addr Valid
Data Valid
Data Valid
Data Valid
Addr Valid
Addr Valid
GPDBUFOE
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...