Chapter 12 Clock Output/Buzzer Output Controller; Functions Of Clock Output/Buzzer Output Controller; Block Diagram Of Clock Output/Buzzer Output Controller - NEC 78K0 User Manual

CHAPTER 12 CLOCK OUTPUT/BUZZER OUTPUT CONTROLLER

12.1 Functions of Clock Output/Buzzer Output Controller

The clock output controller is intended for carrier output during remote controlled transmission and clock output for
supply to peripheral LSIs. The clock selected with the clock output selection register (CKS) is output.
In addition, the buzzer output is intended for square-wave output of buzzer frequency selected with CKS.
Figure 12-1 shows the block diagram of clock output/buzzer output controller.
Figure 12-1. Block Diagram of Clock Output/Buzzer Output Controller
f
X
f
XT
BZOE BCS1 BCS0
272
Prescaler
10
f /2 to f
8 4
X
7
f to f /2
X X
CLOE CCS3 CCS2 CCS1
Clock output selection register (CKS)
Internal bus
User's Manual U15947EJ2V0UD
13
/2
X
Output latch
PM141
(P141)
BZOE
BCS0, BCS1
Clock
controller
CLOE
Output latch
*
(P140)
CCS0
BUZ/BUSY0/
INTP7/P141
PCL/INTP6/P140
PM140