h8s-2635 Renesas Electronics Corporation., h8s-2635 Datasheet - Page 850

• Manufacturer Part Number: h8s-2635
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

Section 21A ROM (H8S/2636 Group)
21A.14 Flash Memory and Power-Down States
In addition to its normal operating state, the flash memory has power-down states in which power
consumption is reduced by halting part or all of the internal power supply circuitry.
There are three flash memory operating states:
(1) Normal operating mode: The flash memory can be read and written to.
(2) Power-down mode: Part of the power supply circuitry is halted, and the flash memory can be
(3) Standby mode: All flash memory circuits are halted, and the flash memory cannot be read or
States (2) and (3) are flash memory power-down states. Table 21A-26 shows the correspondence
between the operating states of the LSI and the flash memory.
Table 21A-26
Note: * Subclock functions (subactive mode, subsleep mode, and watch mode) are available in the
21A.14.1 Notes on Power-Down States
1. When the flash memory is in a power-down state, part or all of the internal power supply
Rev. 6.00 Feb 22, 2005 page 790 of 1484
REJ09B0103-0600
LSI Operating State
High-speed mode
Medium-speed mode
Sleep mode
Subactive mode *
Subsleep mode *
Watch mode *
Software standby mode
Hardware standby mode
read when the LSI is operating on the subclock * .
written to.
circuitry is halted. Therefore, a power supply circuit stabilization period must be provided
when returning to normal operation. When the flash memory returns to its normal operating
state from a power-down state, bits STS2 to STS0 in SBYCR must be set to provide a wait
time of at least 20 µs (power supply stabilization time), even if an oscillation stabilization
period is not necessary.
U-mask version only.
These functions cannot be used with the other versions.
Flash Memory Operating States
Flash Memory Operating State
Normal mode (read/write)
When PDWND = 0: Power-down mode (read-only)
When PDWND = 1: Normal mode (read-only)
Standby mode