162 Hitachi
Figure 7.25 Auto-Refresh Timing
Self-Refreshes: The self-refresh mode is a type of standby mode that produces refresh timing and
refresh addresses within the synchronous DRAM. It is started up by setting the RMODE and
RFSH bits to 1. The synchronous DRAM is in self-refresh mode when the CKE signal level is
low. During the self refresh, the synchronous DRAM cannot be accessed. To clear the self refresh,
set the RMODE bit to 0. After self-refresh mode is cleared, issuing of commands is prohibited for
the number of cycles specified in the MCR’s TRAS bit + 1 cycle. Figure 7.26 shows the self-
refresh timing. Immediately set the synchronous DRAM so that the auto refresh is performed in
the correct interval. This ensures a correct self-refresh clear and data holding. When self refresh is
entered while the synchronous DRAM is set for auto refresh or when leaving the standby mode
with a manual reset or NMI, auto refresh can be re-started if the RFSH is 1 and RMODE is 0 when
the self-refresh mode is cleared. When time is required between clearing the self-refresh mode and
starting the auto-refresh mode, this time must be reflected in the initial RTCNT setting. When the
RTCNT value is set to RTCOR – 1, the refresh can be started immediately.
If the standby function of the SH7095 is used after the self refresh is set to enter the standby mode,
the self-refresh state continues; the self-refresh state will also be maintained after returning from a
standby using an NMI.
Manual reset cannot be used to get out of self refresh either. During a power-on reset, the bus state
controller register is initialized, so the self-refresh state is ended.
Refresh Requests and Bus Cycle Requests: When a refresh request occurs while a bus cycle is
executing, the refresh will not be executed until the bus cycle is completed. When a refresh request
occurs while the bus is released using the bus arbitration function, the refresh will not be executed
until the bus is recaptured. If RTCNT and RTCOR match and a new refresh request occurs while
waiting for the refresh to execute, the previous refresh request is erased. To make sure the refresh
executes properly, be sure that the bus cycle and bus capture do not exceed the refresh interval.
If a bus arbitration request occurs during a self refresh, the bus is not released until the self refresh
is cleared. During self refresh, the slave chips halt if there is a master-slave structure.
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 ...