Z86D991屬于集成電路（IC）的微控制器。由Zilog, Inc.制造生產的Z86D991微控制器微控制器產品是相對復雜的用戶可編程數字邏輯器件。這些產品與視為微控制器的器件密切相關，兩者之間的區(qū)別主要體現在制造商選擇的用詞。不過按照傳統(tǒng)，微控制器集成了工作存儲器，也更可能包含混合信號外設，并且往往與更簡單的軟件范例結合使用，旨在重復執(zhí)行一系列預定義的任務。

Architectural Overview

The Z86D99 is a low-voltage general-purpose one-time programmable (OTP) Z8? microcontroller with an integrated four-channel 8-bit sigma delta analog-to-digital converter. The Z86L99 is the read-only memory (ROM) version of this controller.

特性 Features

? Four-channel, 8-bit sigma delta analog-to-digital (A/D) converter with external

voltage references (not available in the 28-pin configuration)

? Two independent analog comparators

? Controlled current output

? 489 bytes of RAM

– 233 bytes of general-purpose register-based RAM

– 256 bytes of RAM mapped into the program memory space that can be

used as data RAM or executable RAM

? 32 Kbytes of OTP memory (Z86D99X)

? 16 Kbytes of ROM (Z86L99X)

Counter/Timers

? Special architecture to automate generation and reception of complex pulses

or signals:

– Programmable 8-bit counter/timer (T8) with two 8-bit capture registers and

two 8-bit load registers

– Programmable 16-bit counter/timer (T16) with one 16-bit capture register

pair and one 16-bit load register pair

– Programmable input glitch filter for pulse reception

? One general-purpose 8-bit counter/timer (T1) with 6-bit prescaler

Input/Output and Interrupts

? Thirty-two I/Os, twenty-nine of which are bidirectional I/Os with programmable

resistive pull-up transistors (24 I/Os are available in the 28-pin configuration)

? Sixteen I/Os are selectable as stop-mode recovery sources

? Six interrupt vectors with nine interrupt sources

– Three external sources

– Two comparator interrupts

– Three timer interrupts

– One low-battery detector flag

Operating Characteristics

? 8-MHz operation

? 3.0 V to 5.5 V operating voltage (Z86D990/Z86D991)

? 2.3 V to 5.5 V operating voltage (Z86L990/Z86L991)

? Low power consumption with three standby modes:

– Stop

– Halt

– Low Voltage Standby

? Low-battery detection flag

? Low-voltage protection circuit (also known as VBO, or voltage brownout,

circuit)

? Watch-dog timer and power-on reset circuits

User-Programmable Option Bits

? Clock source—RC/other (LC, resonator, or crystal)

? Watch-dog timer permanently enable

? 32-kHz crystal

? Port 20–27 pull-up resistive transistor

? Port 40–42 pull-up resistive transistor

? Port 44–47 pull-up resistive transistor

? Port 50–51 pull-up resistive transistor

? Port 54–57 pull-up resistive transistor

? Port 60–63 pull-up resistive transistor (not available in Z86D991/Z86L991)

? Port 64–67 pull-up resistive transistor (not available in Z86D991/Z86L991)

? P43 high impedance in STOP mode (available in OTP only)

Force P43 to output a 1 in the open-drain configuration