Hitachi 221
Section 9 Direct Memory Access Controller (DMAC)
9.1
Overview
The SH7095 includes a two-channel direct memory access controller (DMAC). The DMAC can
be used in place of the CPU to perform high-speed data transfers between external devices
equipped with DACK (transfer request acknowledge signal), external memories, memory-mapped
external devices, and on-chip peripheral modules (except for the DMAC, BSC and UBC). Using
the DMAC reduces the burden on the CPU and increases operating efficiency of the LSI as a
whole.
9.1.1
Features
The DMAC has the following features:
•
Number of channels: 2
•
Address space: 4 Gbytes on the architecture
•
Selectable data transfer unit: Byte, word (2 bytes), longword (4 bytes) or 16-byte unit (16-
byte transfers first perform four longword reads and then four longword writes)
•
Maximum transfer count: 16,777,216 (16M) transfers
•
With cache hits, CPU instruction processing and DMA operation can proceed in parallel
•
The maximum transfer rate for synchronous DRAM burst transfers is 38 Mbytes/sec (f = 28.7
MHz)
•
Single address mode transfers: Either the transfer source or transfer destination (peripheral
device) is accessed by a DACK signal (selectable) while the other is accessed by address. One
transfer unit of data is transferred in each bus cycle.
Device combinations able to transfer:
— External devices with DACK and memory-mapped external devices (including external
memories)
•
Dual address mode transfers: Both the transfer source and transfer destination are accessed by
address. One transfer unit of data is transferred in two bus cycles.
Device combinations able to transfer:
— Two external memories
— External memory and memory-mapped external devices
— Two memory-mapped external devices
— External memory and on-chip peripheral module (excluding the DMAC, BSC and UBC).
— Memory-mapped external devices and on-chip peripheral modules (excluding the DMAC,
BSC and UBC)
Summary of Contents for SH7095
Page 1: ...SH7095 Hardware User Manual ...
Page 23: ...12 Hitachi ...
Page 63: ...52 Hitachi ...
Page 77: ...66 Hitachi ...
Page 105: ...94 Hitachi Figure 5 14 Pipeline Operation when Interrupts are Enabled by Changing the SR ...
Page 127: ...116 Hitachi ...
Page 152: ...Hitachi 141 Figure 7 8 Example of 32 Bit Data Width SRAM Connection ...
Page 157: ...146 Hitachi Figure 7 13 Synchronous DRAM 32 bit Device Connection ...
Page 161: ...150 Hitachi Figure 7 15 Basic Burst Read Timing Auto Precharge ...
Page 167: ...156 Hitachi Figure 7 20 Burst Read Timing Bank Active Same Row Address ...
Page 168: ...Hitachi 157 Figure 7 21 Burst Read Timing Bank Active Different Row Addresses ...
Page 169: ...158 Hitachi Figure 7 22 Write Timing No Precharge ...
Page 170: ...Hitachi 159 Figure 7 23 Write Timing Bank Active Same Row Address ...
Page 180: ...Hitachi 169 Figure 7 29 Example of a DRAM Connection 32 Bit Data Width ...
Page 190: ...Hitachi 179 Figure 7 36 Example of Pseudo SRAM Connection 1 M pseudo SRAM ...
Page 191: ...180 Hitachi Figure 7 37 Example of Pseudo SRAM Connection 4 M pseudo SRAM ...
Page 209: ...198 Hitachi Figure 7 50 Master and Partial Share Master Connections ...
Page 231: ...220 Hitachi ...
Page 287: ...276 Hitachi ...
Page 307: ...296 Hitachi Note For a CPU writing H AA55 to FRC Figure 11 2 FRC Access Operation Write ...
Page 308: ...Hitachi 297 Note For an FRC reading from a CPU H AA55 Figure 11 3 FRC Access Operation Read ...
Page 333: ...322 Hitachi ...
Page 370: ...Hitachi 359 Figure 13 12 Sample Flowchart for Receiving Multiprocessor Serial Data ...
Page 371: ...360 Hitachi Figure 13 12 Sample Flowchart for Receiving Multiprocessor Serial Data cont ...
Page 395: ...384 Hitachi ...
Page 402: ...Hitachi 391 Figure 15 6 PLL Synchronization Settling Timing ...
Page 408: ...Hitachi 397 Figure 15 13 Bus Release Timing Slave Mode With PLL1 Off ...
Page 436: ...Hitachi 425 Figure 15 33 Synchronous DRAM Mode Register Write Cycle TRP 1 Cycle ...
Page 437: ...426 Hitachi Figure 15 34 Synchronous DRAM Mode Register Write Cycle TRP 2 Cycles ...
Page 449: ...438 Hitachi Figure 15 46 DRAM CAS Before RAS Refresh Cycle TRP 1 Cycle TRAS 2 Cycles PLL On ...
Page 454: ...Hitachi 443 Figure 15 51 DRAM CAS Before RAS Refresh Cycle TRP 1 Cycle TRAS 2 Cycles PLL Off ...
Page 461: ...450 Hitachi Figure 15 58 Pseudo SRAM Auto Refresh Cycle PLL On TRP 1 Cycle TRAS 2 Cycles ...
Page 462: ...Hitachi 451 Figure 15 59 Pseudo SRAM Self Refresh Cycle PLL On TRP 1 Cycle TRAS 2 Cycles ...
Page 467: ...456 Hitachi Figure 15 64 Pseudo SRAM Auto Refresh Cycle PLL Off TRP 1 Cycle TRAS 2 Cycles ...
Page 468: ...Hitachi 457 Figure 15 65 Pseudo SRAM Self Refresh Cycle PLL Off TRP 1 Cycle TRAS 2 Cycles ...
Page 471: ...460 Hitachi Figure 15 68 Interrupt Vector Fetch Cycle PLL On No Waits ...
Page 472: ...Hitachi 461 Figure 15 69 Interrupt Vector Fetch Cycle PLL Off No Waits ...
Page 473: ...462 Hitachi Figure 15 70 Interrupt Vector Fetch Cycle 1 External Wait Cycle ...
Page 474: ...Hitachi 463 Figure 15 71 Address Monitor Cycle ...
Page 490: ...Hitachi 479 B 2 Register Chart ...