HD6477021X20V Renesas Electronics America, HD6477021X20V Datasheet - Page 179

• 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: -

8.10.2
1. BACK Operation
Note: * For details see section 8.11.3, Maximum Number of States from BREQ Input to Bus Release.
BREQ
BACK
BREQ
When an internal refresh is requested during an attempt to assert the BACK signal and BACK
is not asserted but remains high, a momentary narrow pulse-shaped spike may be output, as
shown below.
BREQ
BACK
BACK
BACK Operation
Figure 8.37 BACK Operation in Response to Refresh Request (2)
Refresh request
Figure 8.36 BACK Operation by Refresh Demand (1)
If BACK has not gone low after waiting for the maximum
number of states* before the SuperH releases the bus, return
BREQ to the high level.
Refresh demand
BACK does not go low.
Refresh damand
pulse width of the spike is approx. 2 to 5 ns.
Refresh execution
RENESAS 159