EZ80L92MCU Datasheet, PDF (96/241 Pages) Zilog, Inc. – eZ80Acclaim Flash Microcontrollers

eZ80L92 MCU
Product Specification
81
Programmable Reload Timer Registers
Each programmable reload timer is controlled using five 8-bit registers. These registers
are the Timer Control register, Timer Reload Low Byte register, Timer Reload High Byte
register, Timer Data Low Byte register, and Timer Data High Byte register.
The Timer Control register can be read or written to. The timer reload registers are Write-
Only and are located at the same I/O address as the timer data registers, which are Read-
Only.
Timer Control Registers
The Timer Control register, detailed in Table 32, is used to control operation of the timer,
including enabling the timer, selecting the clock divider, enabling the interrupt, selecting
between CONTINUOUS and SINGLE PASS modes, and enabling the auto-reload fea-
ture.
Table 32. Timer Control Registers (TMR0_CTL = 0080h, TMR1_CTL = 0083h,
TMR2_CTL = 0086h, TMR3_CTL = 0089h, TMR4_CTL = 008Ch, or TMR5_CTL =
008Fh)
Bit
7
6
Reset
0
0
CPU Access
R R/W
Note: R = Read only; R/W = Read/Write.
5
0
R/W
4
0
R/W
3
0
R/W
2
0
R/W
1
0
R/W
0
0
R/W
Bit
Position
7
PRT_IRQ
Value
0
1
6
0
IRQ_EN
1
5
0
4
0
PRT_MODE
1
Description
The timer does not reach its end-of-count value. This bit is
reset to 0 every time the TMRx_CTL register is read.
The timer reaches its end-of-count value. If IRQ_EN is set to 1,
an interrupt signal is sent to the CPU. This bit remains 1 until
the TMRx_CTL register is read.
Timer interrupt requests are disabled.
Timer interrupt requests are enabled.
Reserved.
The timer operates in SINGLE PASS mode. PRT_EN (bit 0) is
reset to 0, and counting stops when the end-of-count value is
reached.
The timer operates in CONTINUOUS mode. The timer reload
value is written to the counter when the end-of-count value is
reached.
PS013012-1004
PRELIMINARY
Programmable Reload Timers