Hitachi 199
7.10.4
External Bus Address Monitor
The master and slave modes have a function to generate break interrupts and monitor the external
bus access cycle using the user break controller. The bus cycle is monitored by sampling the
external bus every time the clock rises while the bus is released. At the time of sampling, when it
is detected that the BS signal is asserted (low level), the address at that time (A26–A0) and
read/write signal RD/WR are fetched and compared as the access address and access type (read or
write).
When an external device has captured the bus and the DRAM or synchronous DRAM is in an
access cycle, the following are important to make the address monitor function correctly.
Synchronizes the time when the BS becomes low in the DRAM or synchronous DRAM access
cycle with the cycle that outputs the column address. Because only the address of the cycle in
which the BS signal is low is fetched and compared, even access to memories like these that
multiplex addresses require outputting of row addresses to the top address bit. One of the bits of
the address signal in the column address output cycle in the synchronous DRAM is used to specify
the bank address, while the other bit is used to specify whether to do an auto precharge. These
always cause breaks on the compared address, so mask these two bits when setting the comparison
address. The masked bit position is described in the section on address multiplexing (7.5.2).
7.10.5
Master and Slave Coordination
Roles must be shared between the master and slave to control system resources without
contradictions. DRAM, synchronous DRAM and pseudo SRAM must be initialized before use.
When using standby operation to lower power consumption, burdens must also be shared.
This SH7095 was designed with the idea that the master mode device would handle all controls,
such as initialization, refresh and standby control. When a 2-processor structure of connected
master and slave is used, all processing except for direct accesses to memory are controlled by the
master. When master mode is combined with partial-share master mode, the partial-share master
mode processor handles initialization, refresh and standby control for all CS spaces connected to it
except for the CS2 space. The master initializes memory connected directly to it.
The hardware or software sequence should be designed so that there are no slave-side processor
accesses until memory that requires initialization before use such as DRAM, synchronous DRAM
and pseudo SRAM has completed its initialization. One method is to install an external circuit that
clears slave resets from the master. Another is to have the master write a flag when initialization is
complete to an SRAM or the like that does not require initialization, and then not to start access
until this flag is acknowledged by the slave. A third method is to install an external circuit that can
send an interrupt from master to slave and clear the slave’s waiting state with an interrupt from the
master to the slave when initialization ends.
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 ...