Hitachi 239
When RXI (transfer request when the SCI’s receive data is full) is set as the transfer request,
however, the transfer source must be the SCI’s receive data register (RDR). Likewise, when TXI
(transfer request when the SCI’s transmit data is empty) is set as the transfer request, the transfer
destination must be the SCI’s transmit data register (TDR).
Table 9.6
Selecting On-Chip Peripheral Module Request Mode with the AR and RS bits
AR
RS1
RS0
DMA Transfer
Request
Source
DMA Transfer
Request Signal
Source Destination
Bus
Mode
DREQ
Setting
0
0
1
SCI receiver
RXI (SCI receive-data-
full transfer request)
RDR0
Any*
Cycle-
steal
Edge, low
active
0
1
0
SCI transmitter TXI (SCI transmit-data-
empty transfer request)
Any*
TDR0
Cycle-
steal
Edge, low
active
Note:
External memory, memory-mapped external device, on-chip peripheral module (excluding
DMAC, BSC, and UBC).
When outputting transfer requests from the SCI, its interrupt enable bits (TIE and RIE) must be set
to output the interrupt signals. Note that transfer request signals from on-chip peripheral modules
(interrupt request signals) are sent not just to the DMAC but to the CPU as well. When an on-chip
peripheral module is specified as the transfer request source, set the priority level values in the
interrupt priority level registers (IPRC–IPRE) of the interrupt controller (INTC) at or below the
levels set in the I3–I0 bits of the CPU’s status register so that the CPU does not accept the
interrupt request signal.
The DMA transfer request signals of table 9.6 are automatically fetched when the corresponding
DMA transfer is performed. If the cycle-steal mode is being employed, DMA transfer requests
(interrupt request) from any module will be cleared at the first transfer; if the burst mode is being
used, it will be cleared at the last transfer.
9.3.3
Channel Priority
When the DMAC receives simultaneous transfer requests on two channels, it selects a channel
according to a predetermined priority. There are two priority modes, fixed and round-robin. The
channel priority is selected by the priority bit PR in the DMA operation register (DMAOR).
Fixed Priority Mode: In this mode, the priority levels among the channels remain fixed. When
PR is set to 0, the priority, high to low, is channel 0 > channel 1. Figure 9.3 shows an example of a
transfer in burst mode.
Содержание SH7095
Страница 1: ...SH7095 Hardware User Manual ...
Страница 16: ...Hitachi 5 1 2 Block Diagram Figure 1 1 is a block diagram of the SH7095 Figure 1 1 Block Diagram ...
Страница 23: ...12 Hitachi ...
Страница 63: ...52 Hitachi ...
Страница 77: ...66 Hitachi ...
Страница 105: ...94 Hitachi Figure 5 14 Pipeline Operation when Interrupts are Enabled by Changing the SR ...
Страница 127: ...116 Hitachi ...
Страница 152: ...Hitachi 141 Figure 7 8 Example of 32 Bit Data Width SRAM Connection ...
Страница 157: ...146 Hitachi Figure 7 13 Synchronous DRAM 32 bit Device Connection ...
Страница 161: ...150 Hitachi Figure 7 15 Basic Burst Read Timing Auto Precharge ...
Страница 167: ...156 Hitachi Figure 7 20 Burst Read Timing Bank Active Same Row Address ...
Страница 168: ...Hitachi 157 Figure 7 21 Burst Read Timing Bank Active Different Row Addresses ...
Страница 169: ...158 Hitachi Figure 7 22 Write Timing No Precharge ...
Страница 170: ...Hitachi 159 Figure 7 23 Write Timing Bank Active Same Row Address ...
Страница 178: ...Hitachi 167 a Phase Shifted 90 by PLL b Phase Shift Using PLL is 0 Figure 7 28 Phase Shift with the PLL ...
Страница 180: ...Hitachi 169 Figure 7 29 Example of a DRAM Connection 32 Bit Data Width ...
Страница 190: ...Hitachi 179 Figure 7 36 Example of Pseudo SRAM Connection 1 M pseudo SRAM ...
Страница 191: ...180 Hitachi Figure 7 37 Example of Pseudo SRAM Connection 4 M pseudo SRAM ...
Страница 209: ...198 Hitachi Figure 7 50 Master and Partial Share Master Connections ...
Страница 218: ...Hitachi 207 EX Instruction execution MA Memory Access WB Write back Figure 8 3 Reading during a Cache Hit ...
Страница 231: ...220 Hitachi ...
Страница 287: ...276 Hitachi ...
Страница 307: ...296 Hitachi Note For a CPU writing H AA55 to FRC Figure 11 2 FRC Access Operation Write ...
Страница 308: ...Hitachi 297 Note For an FRC reading from a CPU H AA55 Figure 11 3 FRC Access Operation Read ...
Страница 333: ...322 Hitachi ...
Страница 370: ...Hitachi 359 Figure 13 12 Sample Flowchart for Receiving Multiprocessor Serial Data ...
Страница 371: ...360 Hitachi Figure 13 12 Sample Flowchart for Receiving Multiprocessor Serial Data cont ...
Страница 395: ...384 Hitachi ...
Страница 402: ...Hitachi 391 Figure 15 6 PLL Synchronization Settling Timing ...
Страница 405: ...394 Hitachi Figure 15 7 Reset Input Timing Figure 15 8 Interrupt Signal Input Timing With PLL1 Off ...
Страница 408: ...Hitachi 397 Figure 15 13 Bus Release Timing Slave Mode With PLL1 Off ...
Страница 436: ...Hitachi 425 Figure 15 33 Synchronous DRAM Mode Register Write Cycle TRP 1 Cycle ...
Страница 437: ...426 Hitachi Figure 15 34 Synchronous DRAM Mode Register Write Cycle TRP 2 Cycles ...
Страница 439: ...428 Hitachi Figure 15 36 Synchronous DRAM Auto Refresh Cycle Shown From Precharge Cycle TRP 1 Cycle TRAS 2 Cycles ...
Страница 449: ...438 Hitachi Figure 15 46 DRAM CAS Before RAS Refresh Cycle TRP 1 Cycle TRAS 2 Cycles PLL On ...
Страница 454: ...Hitachi 443 Figure 15 51 DRAM CAS Before RAS Refresh Cycle TRP 1 Cycle TRAS 2 Cycles PLL Off ...
Страница 461: ...450 Hitachi Figure 15 58 Pseudo SRAM Auto Refresh Cycle PLL On TRP 1 Cycle TRAS 2 Cycles ...
Страница 462: ...Hitachi 451 Figure 15 59 Pseudo SRAM Self Refresh Cycle PLL On TRP 1 Cycle TRAS 2 Cycles ...
Страница 467: ...456 Hitachi Figure 15 64 Pseudo SRAM Auto Refresh Cycle PLL Off TRP 1 Cycle TRAS 2 Cycles ...
Страница 468: ...Hitachi 457 Figure 15 65 Pseudo SRAM Self Refresh Cycle PLL Off TRP 1 Cycle TRAS 2 Cycles ...
Страница 471: ...460 Hitachi Figure 15 68 Interrupt Vector Fetch Cycle PLL On No Waits ...
Страница 472: ...Hitachi 461 Figure 15 69 Interrupt Vector Fetch Cycle PLL Off No Waits ...
Страница 473: ...462 Hitachi Figure 15 70 Interrupt Vector Fetch Cycle 1 External Wait Cycle ...
Страница 474: ...Hitachi 463 Figure 15 71 Address Monitor Cycle ...
Страница 490: ...Hitachi 479 B 2 Register Chart ...