tmp19a43fd TOSHIBA Semiconductor CORPORATION, tmp19a43fd Datasheet - Page 56

• Manufacturer Part Number: tmp19a43fd
• Description: 32-bit Risc Microprocessor
• Manufacturer: TOSHIBA Semiconductor CORPORATION

TMP19A43
10) ID-Read
Using the ID-Read command, you can obtain the type and other information on the flash memory
contained in the device. The data to be loaded will be different depending on the address [15:14] of
the fourth and subsequent bus write cycles (any input data other than 0xF can be used). On and
after the fourth bus write cycle, when an LW command (to read an arbitrary flash memory area) is
executed after an SW command, the ID value will be loaded (execute a SYNC command
immediately after the LW command). Once the fourth bus write cycle of an ID-Read command has
passed, the device will not automatically return to the read mode. In this condition, the set of the
fourth bus write cycle and LW/SYNC commands can be repetitively executed. For returning to the
read mode, reset the system or use the Read or Read/reset command.
The ID-Read command can be used when it is necessary for an application to identify whether the
device in the product has an internal flash memory or an internal ROM. This is effective because a
mask ROM doesn't have a command sequencer so it interprets any ID-Read command written as
simply a pair of SW and LW commands applied to the mask ROM. If an ID-Read command is to
be executed on a device with an internal mask ROM, it is necessary to select an address at which
the rt value to a normal LW command is different from the ID-Read execution result (ID) from a
device with an internal flash memory, also taking into account any applicable protection conditions.
(Important) The "interval between bus write cycles" between successive command sequences
must be 15 system clock cycles or longer irrespective of the operating frequency used. This device
doesn't have any function to automatically adjust the interval between bus write cycles regarding
execution of multiple SW commands to the flash memory. Therefore, if an inadequate interval is
used between two sets of bus write cycles, the flash memory cannot be written as expected. Prior to
setting the device to work in the onboard programming mode, adjust the bus write cycle interval
using a software timer, etc., to verify that the ID-Read command can be successfully executed at
the operating frequency of the application program. In the onboard programming mode, use the bus
write cycle interval at which the ID-Read command can be operated normally to execute command
sequences to rewrite the flash memory.
TMP19A43 (rev2.0)3-42
Flash Memory Operation