UPD784026 Renesas Electronics Corporation., UPD784026 Datasheet - Page 682

• Manufacturer Part Number: UPD784026
• Description: 16/8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

elapsed (approx. 40 ms, depending on the resonator used).
642
In a reset operation upon powering on, the RESET signal must be kept active until the oscillation stabilization time has
Remark f
* 1. In the PD784021 these pins function as the address/data bus, and output signals to fetch the reset vector address
2. In the PD784021, these pins operate as output port pins only, and output “0” after reset release.
Internal Reset Signal
from address 0000H (see Figure 23-3 (a)).
P00-P07
P10/PWM0-P17
P20/NMI-P27/SI
P30/RxD-P37/TO3
P40/AD0-P47/AD7
P50/A8-P57/A15
P60/A16-P63/A19
P64/RD, P65/WR
P66/WAIT, P67/REFRQ
P70/ANI0-P77/ANI7
ASTB/CLKOUT
ANO0, ANO1
CLK
: Internal system clock frequency
RESET
Pin Name
(Input)
V
DD
Table 23-1 Pin Statuses During Reset Input and After Reset Release
*2
Oscillation Stabilization Time
Figure 23-2 Power-On Reset Operation
Input/Output
Input/output
Input/output
Input/output
Input/output
Input/output
Input/output
Input/output
Input/output
Input/output
Output
Output
CHAPTER 23 RESET FUNCTION
Input
On Reset
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Delay PC Initialization, etc.
Reset End
Hi-Z (input port mode)
Hi-Z (input port mode)
Hi-Z (input port)
Hi-Z (input port mode)
Hi-Z (input port mode)
Hi-Z (input port mode)
Hi-Z (input port mode)
Hi-Z (input port mode)
Hi-Z (input port mode)
Hi-Z (input port mode)
0
Outputs AV
Directly After Reset Release
REF3
Execution of Instruction at
Reset Start Address
pin input voltage
*1
*1
*1
*1