Hitachi 371
13.4
SCI Interrupt Sources and the DMAC
The SCI has four interrupt sources in each channel. transmit-end (TEI), receive-error (ERI),
receive-data-full (RXI), and transmit-data-empty (TXI). Table 13.13 lists the interrupt sources and
indicates their priority. These interrupts can be enabled and disabled by the TIE, RIE, and TEIE
bits in the serial control register (SCR). Each interrupt request is sent separately to the interrupt
controller.
TXI is requested when the TDRE bit in the SSR is set to 1. TXI can start the direct memory access
controller (DMAC) to transfer data. TDRE is automatically cleared to 0 when the DMAC writes
data in the transmit data register (TDR).
RXI is requested when the RDRF bit in the SSR is set to 1. RXI can start the DMAC to transfer
data. RDRF is automatically cleared to 0 when the DMAC reads the receive data register (RDR).
ERI is requested when the ORER, PER, or FER bit in the SSR is set to 1. ERI cannot start the
DMAC.
TEI is requested when the TEND bit in the SSR is set to 1. TEI cannot start the DMAC. Where the
TXI interrupt indicates that transmit data writing is enabled, the TEI interrupt indicates that the
transmit operation is complete.
Table 13.13 SCI Interrupt Sources
Interrupt Source
Description
DMAC Availability
Priority
ERI
Receive error (ORER, PER, or FER)
No
High
RXI
Receive data full (RDRF)
Yes
↑
TXI
Transmit data empty (TDRE)
Yes
↓
TEI
Transmit end (TEND)
No
Low
See section 4, Exception Processing, for information on the priority order and relationship to non-
SCI interrupts.
13.5
Notes on Use
Note the following points when using the SCI.
TDR Write and TDRE Flags: The TDRE bit in the serial status register (SSR) is a status flag
indicating loading of transmit data from the TDR into the TSR. The SCI sets TDRE to 1 when it
transfers data from the TDR to the TSR. Data can be written to the TDR regardless of the TDRE
bit status. If new data is written in the TDR when TDRE is 0, however, the old data stored in the
TDR will be lost because the data has not yet been transferred to the TSR. Before writing transmit
data to the TDR, be sure to check that TDRE is set to 1.
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 ...
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Страница 105: ...94 Hitachi Figure 5 14 Pipeline Operation when Interrupts are Enabled by Changing the SR ...
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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 ...
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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 ...
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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 ...
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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 ...