HD6477021X20V Renesas Electronics America, HD6477021X20V Datasheet - Page 156

• Manufacturer Part Number: HD6477021X20V
• Description: MCU 5V 32K PB-FREE 100-TQFP
• Manufacturer: Renesas Electronics America
• Series: SuperH® SH7020r

Specifications of HD6477021X20V

• Core Processor: SH-1
• Core Size: 32-Bit
• Speed: 20MHz
• Connectivity: EBI/EMI, SCI
• Peripherals: DMA, POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: OTP
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 100-TQFP, 100-VQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -

8.5.2
There are two types of DRAM accesses: short pitch and long pitch. Short pitch or long pitch can
be selected for the respective bus cycles using the RW1 and WW1 bits of WCR1 and the DRW1
and DWW1 bits of WCR2. When the corresponding bits are cleared to 0, DRAM access is short
pitch and column address output occurs in 1 state. When these bits are 1, DRAM access is long
pitch and column address output occurs in 2 states. Figure 8.17 shows short pitch timing; figure
8.18 shows long pitch timing.
The high-level duty of the CAS signal can also be selected between 50% and 35% of the T
when access is short pitch. By setting the CDTY bit to 1, high level duty becomes 35% and
DRAM access time can be lengthened. Only set to 1 when the operating frequency is a minimum
of 10 MHz.
136 RENESAS
RAS = Low level
CAS = Low level
Basic Timing
Internal address
Internal address
Address pin
Address pin
Figure 8.16 Address Multiplexing States (8-bit shift)
A23
A23 A22 A21
Undefined output
A21
A21
A16 A15
A8 A7
A0
A0
A0
A0
C
state