NEC mPD780852 Series, Preliminary User'S Manual

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CHAPTER 18 METER CONTROLLER/DRIVER
Preliminary User’s Manual U14581EJ3V0UM00
Figure 18-2. 1-Bit Addition Circuit Block Diagram
Remark n = 1 to 4, m = 0, 1
18.2 Meter Controller/Driver Configuration
The meter controller/driver consists of the following hardware.
Table 18-1. Meter Controller/Driver Configuration
Item Configuration
Timer Free-running up counter (MCNT): 1 channel
Register Compare register (MCMPn1, MCMPn0): 8 channels
Control registers Timer mode control register (MCNTC)
Compare control register n (MCMPCn)
Port mode control register (PMC)
Pulse controller 1-bit addition circuit/output controller
Remark n = 1 to 4
(1) Free-running up counter (MCNT)
MCNT is an 8-bit free-running up counter, and is a register that executes increment at the rising edge of input
clock.
A PWM pulse with a resolution of 8 bits can be output. The duty factor can be set in a range of 0% to 100%.
The count value is cleared in the following cases.
• RESET input
• Stop counter (PCE = 0)
Cautions 1. MCNT executes counting operation from 01H to FFH repeatedly. However, it counts from
00H upon operation start.
2. The PWM output is not output until the first overflow of MCNT.
Internal bus
f
tCC
OVF
Compare register
(MCMPnm)
Q
S
R
Q
S
Selector
ADBn1 ADBn0
Compare control register (MCMPCn)
2