HD64F2638F20J Renesas Electronics America, HD64F2638F20J Datasheet - Page 790

• Manufacturer Part Number: HD64F2638F20J
• Description: IC H8S MCU FLASH 256K 128-QFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2600r

Specifications of HD64F2638F20J

• Core Processor: H8S/2600
• Core Size: 16-Bit
• Speed: 20MHz
• Connectivity: CAN, SCI, SmartCard
• Peripherals: Motor Control PWM, POR, PWM, WDT
• Number Of I /o: 72
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 16K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 12x10b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 128-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

Section 20 RAM
20.2
20.2.1
The on-chip RAM is enabled or disabled by the RAME bit in SYSCR. For details of other bits in
SYSCR, see section 3.2.2, System Control Register (SYSCR).
Bit 0—RAM Enable (RAME): Enables or disables the on-chip RAM. The RAME bit is
initialized when the reset state is released. It is not initialized in software standby mode.
Bit 0
RAME
0
1
20.3
When the RAME bit is set to 1, accesses to addresses H'FFE000 to H'FFEFBF (for the H8S/2636),
H'FFB000 to H'FFEFBF (for the H8S/2638, H8S/2639, and H8S/2630), H'FFD800 to H'FFEFBF
(for the H8S/2635 Group), or H'FFFFC0 to H'FFFFFF in the chip are directed to the on-chip
RAM. When the RAME bit is cleared to 0, the off-chip address space is accessed.
Since the on-chip RAM is connected to the CPU by an internal 16-bit data bus, it can be written to
and read in byte or word units. Each type of access can be performed in one state.
Even addresses use the upper 8 bits, and odd addresses use the lower 8 bits. Word data must start
at an even address.
Page 740 of 1458
Bit
Initial value
R/W
Register Descriptions
System Control Register (SYSCR)
Operation
Description
On-chip RAM is disabled
On-chip RAM is enabled
:
:
:
MACS
R/W
7
0
⎯
⎯
6
0
INTM1
R/W
5
0
INTM0
R/W
4
0
NMIEG
R/W
3
0
R/W
⎯
2
0
H8S/2639, H8S/2638, H8S/2636,
REJ09B0103-0800 Rev. 8.00
H8S/2630, H8S/2635 Group
⎯
⎯
1
0
(Initial value)
RAME
May 28, 2010
R/W
0
1